{"id":534675,"date":"2026-07-17T17:54:06","date_gmt":"2026-07-17T21:54:06","guid":{"rendered":"https:\/\/www.fs1inc.com\/blog\/?p=534675"},"modified":"2026-07-19T12:25:34","modified_gmt":"2026-07-19T16:25:34","slug":"2003-pontiac-sunfire-pcm-replacement-guide","status":"publish","type":"post","link":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/","title":{"rendered":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &#038; Faults"},"content":{"rendered":"<div class=\"container\">\n<section class=\"hero\">\n<div class=\"code-badge\">PCM<\/div>\n<h1>2003 Pontiac Sunfire PCM: Replacement, Reprogramming &amp; Faults<\/h1>\n<p class=\"hero-subtitle\">The Powertrain Control Module in your 2003 Pontiac Sunfire manages engine timing, fuel delivery, and transmission shifting through sensor inputs. When internal circuitry fails, the module may lose calibration data, set fault codes, or cause drivability problems requiring replacement and reprogramming.<\/p>\n<\/section>\n<div class=\"quick-summary\">\n<h2>Quick Summary<\/h2>\n<ul>\n<li>PCM failure on the Sunfire often sets module-internal fault codes (P0600 series) rather than sensor-related codes<\/li>\n<li>Factory procedure requires the ignition to be OFF when disconnecting the PCM connector to avoid internal damage<\/li>\n<li>The replacement PCM must be reprogrammed and the crankshaft position system variation learn procedure must be performed after installation<\/li>\n<li>Both engine control module removal and reinstall typically require around 0.8 hours of labor each, plus additional time for relearn procedures<\/li>\n<li>Service bulletins from late 2003 address PCM software issues causing neutral flare, no upshift, and illumination of the Service Engine Soon light<\/li>\n<\/ul>\n<\/div>\n<div class=\"info-section\">\n<p>Your 2003 Pontiac Sunfire may experience symptoms pointing to a failing Powertrain Control Module, including hard starting, stalling, unexpected gear shifting behavior, or illumination of the Service Engine Soon light. The PCM serves as the central computer for the 2.2L engine, and when internal circuitry degrades, the vehicle may run poorly or set codes that do not clear with sensor replacement alone. This article explains what the PCM does in your specific vehicle, where it is located, what replacement and reprogramming involve, and how to recognize when the module itself is the root cause rather than a faulty sensor. You will gain a clear understanding of the repair process, the factory cautions that protect your vehicle during service, and the steps needed to restore normal operation.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>What the PCM Does in a 2003 Pontiac Sunfire<\/h2>\n<p>The Powertrain Control Module in your 2003 Pontiac Sunfire serves as the central computer responsible for managing the 2.2L engine and the automatic transmission as a single integrated system. It processes inputs from the crankshaft position sensor, camshaft position sensor, manifold absolute pressure sensor, and other components to calculate fuel injector pulse width, ignition timing advance, and transmission shift points in real time. This coordination keeps your vehicle running smoothly under varying loads and speeds. Your Sunfire&#8217;s PCM stores this calibration data in non-volatile memory, which can become corrupted over time due to voltage spikes, heat cycles, or normal aging of internal circuitry. When this happens, the module may set internal fault codes such as P0601 or P0602, fail to communicate with a scan tool, or cause drivability symptoms that persist despite replacing sensors. In these cases, installing replacement engine computers for the Sunfire becomes necessary to restore proper engine and transmission operation.<\/p>\n<p>Flagship One keeps <a href=\"https:\/\/www.fs1inc.com\/gm\/pontiac-pcm-ecm-ecu-engine-computer\/sunfire-engine-computers.html\">Pontiac Sunfire replacement engine computers<\/a> in stock for exactly this failure pattern.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Where the PCM Is Located and What Replacement Involves<\/h2>\n<p>The Powertrain Control Module on the 2003 Pontiac Sunfire is typically located in the engine compartment, secured to the firewall or a mounting bracket. Access requires working in a cramped space, and the factory cautions that the ignition must be turned OFF before disconnecting the module connector to prevent internal damage to the unit. The removal procedure involves unplugging the electrical connector, removing the mounting fasteners, and lifting the module free. Reinstallation reverses this process. Book time for Powertrain Control Module removal and reinstall on your vehicle is 0.8 hours per operation. After the module is physically installed, a relearn procedure requiring an additional 0.5 hours may be necessary to allow the new PCM to adapt to your specific vehicle&#8217;s engine characteristics and sensor calibration values. Proper torque of mounting fasteners ensures the module remains secure during vehicle operation.<\/p>\n<figure style=\"margin:22px auto;text-align:center;max-width:720px\"><img decoding=\"async\" style=\"max-width:100%;height:auto;border:1px solid #e2e6ec;border-radius:8px\" src=\"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp\" alt=\"2003 Pontiac Sunfire PCM location diagram\" loading=\"lazy\"\/><figcaption style=\"font-size:13px;color:#667085;margin-top:8px\">From the factory PCM removal procedure for the 2003 Pontiac Sunfire.<\/figcaption><\/figure>\n<div style=\"background:#f7f9fc;border:1px solid #e2e8f2;border-radius:10px;padding:18px 24px;margin:18px 0\">\n<h3 style='margin-top:0'>How to Reach the PCM on the 2003 Pontiac Sunfire<\/h3>\n<ol style=\"margin:14px 0 6px 0;padding-left:26px\">\n<li style=\"margin:10px 0;line-height:1.65\"><b>Disconnect<\/b> the negative battery cable.<\/li>\n<li style=\"margin:10px 0;line-height:1.65\"><b>Press<\/b> the PCM retaining tab.<\/li>\n<li style=\"margin:10px 0;line-height:1.65\"><b>Lift<\/b> the PCM from the PCM.<\/li>\n<li style=\"margin:10px 0;line-height:1.65\"><b>Remove<\/b> the new PCM from the packaging and inspect the service.<\/li>\n<li style=\"margin:10px 0;line-height:1.65\"><b>Position<\/b> system variation learn procedure must be performed.<\/li>\n<\/ol>\n<p style='margin:10px 0 0 0'><em>Work with the ignition off, and treat the module as static-sensitive: avoid touching the connector pins at any point.<\/em><\/p>\n<\/div>\n<table style=\"width:100%;border-collapse:collapse;margin:18px 0;font-size:15px\">\n<tr>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Operation<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Configuration<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Book Time<\/th>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Engine Control Module R&amp;R<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">All configurations<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">0.8 hr<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Powertrain Control Module Relearn<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">All configurations<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">0.5 hr<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Powertrain Control Module R&amp;R<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">All configurations<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">0.8 hr<\/td>\n<\/tr>\n<\/table>\n<\/div>\n<div class=\"info-section\">\n<h2>Programming Requirements After Replacement<\/h2>\n<p>Following installation of a replacement PCM, the factory service procedure requires that the module be reprogrammed and the crankshaft position system variation learn procedure be performed on your 2003 Pontiac Sunfire. This process aligns the new module&#8217;s internal memory with your specific engine&#8217;s crankshaft and camshaft position sensor signals, ensuring accurate timing and fuel delivery. Without this step, the engine may run roughly or fail to start properly. Flagship One units are shipped as a VIN-programmed replacement unit, which means the module arrives with your vehicle&#8217;s specific calibration already loaded. This eliminates the need for you to source programming equipment or visit a dealership for the initial flash programming step, though the crankshaft position variation learn procedure may still need to be completed with a properly equipped scan tool.<\/p>\n<p>Every <a href=\"https:\/\/www.fs1inc.com\/2003-pontiac-sunfire-2-2l-engine-computer-pcm-ecm-ecu-programmed-plug-play.html\">VIN-programmed replacement unit<\/a> from Flagship One arrives with these steps already completed.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Symptoms of a Failing PCM<\/h2>\n<p>When the Powertrain Control Module begins to fail on your 2003 Pontiac Sunfire, you may notice a range of symptoms that vary depending on which internal circuit is affected. Common signs include a no-start condition where the engine cranks but fails to fire, stalling at idle or during deceleration, and misfire codes such as P0300 that do not correspond to a faulty ignition component. Some owners report that the scan tool cannot establish communication with the vehicle, which points directly to a failed control module. Transmission shifting problems are also common, including failure to upshift, harsh gear engagements, or neutral flare during acceleration. These issues may be accompanied by illumination of the Service Engine Soon light and the setting of <a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0601-internal-control-module-memory-checksum-error\/\">internal memory failure<\/a> codes, which indicate that the module&#8217;s internal memory has detected an error. If your vehicle exhibits any combination of these symptoms, especially following a battery jump-start or electrical repair, the PCM itself may be the culprit rather than individual sensors.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Module Trouble Codes on the 2003 Pontiac Sunfire<\/h2>\n<p>The 2003 Pontiac Sunfire may set several module-internal trouble codes when the Powertrain Control Module experiences internal faults. These codes, ranging from P0601 through P1683, indicate various failures within the module&#8217;s processor, memory, or communication circuits rather than problems with external sensors or wiring. When these codes appear without corresponding sensor faults, replacement of the PCM is typically required to resolve the issue.<\/p>\n<table style=\"width:100%;border-collapse:collapse;margin:18px 0;font-size:15px\">\n<tr>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Code<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Meaning<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Full Guide<\/th>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0601-internal-control-module-memory-checksum-error\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0601<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0601-internal-control-module-memory-checksum-error\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Internal memory checksum error<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0601-internal-control-module-memory-checksum-error\/\" style=\"color:#0563C1\"><b><u>Full P0601 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0602-control-module-programming-error\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0602<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0602-control-module-programming-error\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Control module programming error<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0602-control-module-programming-error\/\" style=\"color:#0563C1\"><b><u>Full P0602 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0603-internal-control-module-keep-alive-memory-kam-error\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0603<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0603-internal-control-module-keep-alive-memory-kam-error\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Keep-alive memory (KAM) error<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0603-internal-control-module-keep-alive-memory-kam-error\/\" style=\"color:#0563C1\"><b><u>Full P0603 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0604-internal-control-module-random-access-memory-ram-error\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0604<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0604-internal-control-module-random-access-memory-ram-error\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Internal RAM error<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0604-internal-control-module-random-access-memory-ram-error\/\" style=\"color:#0563C1\"><b><u>Full P0604 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0605-internal-control-module-read-only-memory-rom-error\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0605<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0605-internal-control-module-read-only-memory-rom-error\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Internal ROM error<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0605-internal-control-module-read-only-memory-rom-error\/\" style=\"color:#0563C1\"><b><u>Full P0605 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0606-control-module-processor\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0606<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0606-control-module-processor\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Module processor failure<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0606-control-module-processor\/\" style=\"color:#0563C1\"><b><u>Full P0606 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0607-control-module-performance\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0607<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0607-control-module-performance\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Module performance fault<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0607-control-module-performance\/\" style=\"color:#0563C1\"><b><u>Full P0607 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0621-generator-lampl-terminal-circuit\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0621<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0621-generator-lampl-terminal-circuit\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Module-internal fault<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0621-generator-lampl-terminal-circuit\/\" style=\"color:#0563C1\"><b><u>Full P0621 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0622-generator-fieldf-terminal-circuit\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P0622<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0622-generator-fieldf-terminal-circuit\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Module-internal fault<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0622-generator-fieldf-terminal-circuit\/\" style=\"color:#0563C1\"><b><u>Full P0622 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1600-pcm-battery-voltage-supply-loss-of-communication\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P1600<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1600-pcm-battery-voltage-supply-loss-of-communication\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Loss of communication \/ battery voltage supply fault<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1600-pcm-battery-voltage-supply-loss-of-communication\/\" style=\"color:#0563C1\"><b><u>Full P1600 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1621-control-module-long-term-memory-performance\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P1621<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1621-control-module-long-term-memory-performance\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">Control module long-term memory performance<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1621-control-module-long-term-memory-performance\/\" style=\"color:#0563C1\"><b><u>Full P1621 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1627-control-module-a-d-performance\/\" style=\"color:#0563C1;text-decoration:none;display:block;cursor:pointer\"><b>P1627<\/b><\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1627-control-module-a-d-performance\/\" style=\"color:#1a2b49;text-decoration:none;display:block;cursor:pointer\">A\/D performance fault<\/a><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p1627-control-module-a-d-performance\/\" style=\"color:#0563C1\"><b><u>Full P1627 guide &rarr;<\/u><\/b><\/a><\/td>\n<\/tr>\n<\/table>\n<\/div>\n<div class=\"info-section\">\n<h2>Factory Service Bulletins Worth Knowing<\/h2>\n<p>Factory service bulletins address PCM-related concerns for your 2003 Pontiac Sunfire. Service Bulletin 03064, issued December 17, 2003, covers a system software upgrade for OBD system improvements requiring PCM reprogramming. Service Bulletin 03-07-30-021A, issued November 19, 2003, addresses neutral flare and RPM flare while in drive, no 1-2 upshift, and Service Engine Soon light illumination caused by DTCs P1810 or P1815 being set, with reprogramming of the Powertrain Control Module as the remedy. Service Bulletin 02-06-04-057E, issued March 2, 2006, provides warranty administration guidelines and labor operation assignments for control module reprogramming across all affected vehicles. These bulletins confirm that PCM software issues were a known concern during this model year production run.<\/p>\n<table style=\"width:100%;border-collapse:collapse;margin:18px 0;font-size:15px\">\n<tr>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Bulletin<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">Subject<\/th>\n<th style=\"border:1px solid #d6dbe3;background:#f2f5f9;padding:9px 12px;text-align:left\">What It Addresses<\/th>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">&mdash;<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">System Software Upgrade &#8211; OBD System Improvements (Reprogram PCM) &#8211; (Dec 17, 2003)<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">&mdash;<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><b>03-07-30-021<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Neutral Flare and\/or RPM Flare While In Drive, No 1-2 Upshift, Service Engine Soon (SES) Light <\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Some customers may comment on a neutral flare and\/or RPM increase while in drive or no 1\u20132 upshift and\/or the Service Engine Soon (SES) telltale may be\u2026<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\"><b>02-06-04-057<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Warranty Admin. &#8211; Labor Operation Assignments for All Control Module Reprogramming &#8211; (Mar 2, 20<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">&mdash;<\/td>\n<\/tr>\n<\/table>\n<\/div>\n<div class=\"info-section\">\n<h2>Protecting the PCM in Your 2003 Pontiac Sunfire<\/h2>\n<ul style=\"margin:14px 0 6px 0;padding-left:26px\">\n<li style=\"margin:10px 0;line-height:1.65\">Maintain the charging system in good condition with properly tightened battery terminals and a functioning alternator to prevent voltage fluctuations that can damage PCM circuits<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Avoid jump-starting your vehicle incorrectly by connecting booster cables positive to positive and negative to ground rather than directly to the negative battery terminal<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Keep all PCM electrical connectors clean and dry, ensuring the weatherpack seals remain intact to block moisture intrusion that promotes corrosion<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Address any stored diagnostic trouble codes promptly rather than allowing them to persist, as underlying electrical issues can stress the module over time<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Use caution when performing welding repairs on your vehicle by disconnecting the PCM first to prevent voltage spikes from traveling through the harness<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Minimize exposure of the engine bay to high-pressure washers directed at the PCM location to protect the module housing from moisture intrusion<\/li>\n<\/ul>\n<\/div>\n<div class=\"info-section\">\n<h2>Frequently Asked Questions<\/h2>\n<h3>Will my 2003 Pontiac Sunfire run without a properly programmed PCM?<\/h3>\n<p>No, the vehicle will not run normally without a functioning and properly calibrated Powertrain Control Module. If the module fails entirely, the engine may not start or will run in a severely limited failsafe mode with greatly reduced performance.<\/p>\n<h3>Can I install a used PCM from another Sunfire without reprogramming?<\/h3>\n<p>A used PCM from another vehicle will not work without reprogramming to your specific VIN, unless it is purchased pre-programmed from a supplier such as Flagship One. An unprogrammed unit will not communicate with your engine sensors or allow proper operation.<\/p>\n<h3>What causes the Service Engine Soon light to stay on after PCM replacement?<\/h3>\n<p>If the light remains illuminated after replacement, the new module may not have been properly programmed, the crankshaft position variation learn procedure may not have been completed, or an underlying wiring or sensor issue may still be present that was not resolved by the module replacement.<\/p>\n<\/div>\n<div class=\"info-section\">\n<p>Repair versus replacement is a practical consideration when your 2003 Pontiac Sunfire experiences PCM failure. A failed module cannot be repaired externally, and EEPROM reprogramming requires specialized equipment typically found only at dealerships. For most owners, obtaining a pre-programmed replacement unit eliminates the need for dealer programming appointments and ensures the module is ready to install. Refurbished exchange units may also be available, though you should verify whether programming is included in the purchase price and confirm compatibility with your specific vehicle configuration before ordering.<\/p>\n<figure style=\"margin:22px auto;text-align:center;max-width:720px\"><img decoding=\"async\" style=\"max-width:100%;height:auto;border:1px solid #e2e6ec;border-radius:8px\" src=\"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeD\/gm-pcm-typed-1.jpg\" alt=\"Refurbished VIN-programmed PCM for the 2003 Pontiac Sunfire\" loading=\"lazy\"\/><figcaption style=\"font-size:13px;color:#667085;margin-top:8px\">A refurbished, VIN-programmed replacement PCM for the 2003 Pontiac Sunfire from Flagship One.<\/figcaption><\/figure>\n<p>Flagship One stocks a <a href=\"https:\/\/www.fs1inc.com\/2003-pontiac-sunfire-2-2l-engine-computer-pcm-ecm-ecu-programmed-plug-play.html\"><b>refurbished, VIN-programmed PCM for the 2003 Pontiac Sunfire<\/b><\/a> with a lifetime warranty, free shipping and no core charge. The full <a href=\"https:\/\/www.fs1inc.com\/gm\/pontiac-pcm-ecm-ecu-engine-computer\/sunfire-engine-computers.html\">Pontiac Sunfire module lineup<\/a> covers other engine configurations as well.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Final Thoughts<\/h2>\n<p>The Powertrain Control Module in your 2003 Pontiac Sunfire is a critical component that coordinates engine and transmission operation through complex software calibration. When internal faults occur, the resulting symptoms can mimic sensor failures, making accurate diagnosis essential before committing to replacement. Understanding the location, reprogramming requirements, and factory cautions helps you approach the repair with confidence and avoid unnecessary comebacks on your 2003 Pontiac Sunfire.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Diagnose and replace the PCM on your 2003 Pontiac Sunfire. Learn about module failure symptoms, installation steps, reprogramming requirements, and common fault codes that trigger replacement.<\/p>\n","protected":false},"author":1,"featured_media":526045,"comment_status":"open","ping_status":"closed","sticky":false,"template":"elementor_header_footer","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[258,474],"tags":[388,72,664],"class_list":["post-534675","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-car","category-pontiac","tag-388","tag-pontiac","tag-sunfire"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>2003 Pontiac Sunfire PCM: Replacement, Reprogramming &amp; Faults - Flagship One Blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &amp; Faults - Flagship One Blog\" \/>\n<meta property=\"og:description\" content=\"Diagnose and replace the PCM on your 2003 Pontiac Sunfire. Learn about module failure symptoms, installation steps, reprogramming requirements, and common fault codes that trigger replacement.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/\" \/>\n<meta property=\"og:site_name\" content=\"Flagship One Blog\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/flagshipone\" \/>\n<meta property=\"article:author\" content=\"https:\/\/www.facebook.com\/flagshipone\/\" \/>\n<meta property=\"article:published_time\" content=\"2026-07-17T21:54:06+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-19T16:25:34+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp\" \/>\n\t<meta property=\"og:image:width\" content=\"677\" \/>\n\t<meta property=\"og:image:height\" content=\"610\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/webp\" \/>\n<meta name=\"author\" content=\"FlagshipOne\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@theflagshipone\" \/>\n<meta name=\"twitter:site\" content=\"@theflagshipone\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"FlagshipOne\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"9 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/\"},\"author\":{\"name\":\"FlagshipOne\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#\\\/schema\\\/person\\\/a3cf463514bd03eb7656953ef8f75700\"},\"headline\":\"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &#038; Faults\",\"datePublished\":\"2026-07-17T21:54:06+00:00\",\"dateModified\":\"2026-07-19T16:25:34+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/\"},\"wordCount\":1894,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/2003-pontiac-sunfire-pcm-service-figure.webp\",\"keywords\":[\"2003\",\"Pontiac\",\"Sunfire\"],\"articleSection\":[\"Car\",\"Pontiac\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/\",\"name\":\"2003 Pontiac Sunfire PCM: Replacement, Reprogramming & Faults - Flagship One Blog\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/2003-pontiac-sunfire-pcm-service-figure.webp\",\"datePublished\":\"2026-07-17T21:54:06+00:00\",\"dateModified\":\"2026-07-19T16:25:34+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/2003-pontiac-sunfire-pcm-service-figure.webp\",\"contentUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2026\\\/07\\\/2003-pontiac-sunfire-pcm-service-figure.webp\",\"width\":677,\"height\":610,\"caption\":\"Figure from the factory control-module removal procedure for the 2003 Pontiac Sunfire\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/2003-pontiac-sunfire-pcm-replacement-guide\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &#038; Faults\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/\",\"name\":\"Flagship One Blog\",\"description\":\"Flagship One Inc. OEM Engine Computers  Control Modules\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#organization\",\"name\":\"Flagship One, Inc.\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2019\\\/06\\\/web-lg-fs1-logo.png\",\"contentUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/wp-content\\\/uploads\\\/2019\\\/06\\\/web-lg-fs1-logo.png\",\"width\":1341,\"height\":1098,\"caption\":\"Flagship One, Inc.\"},\"image\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/flagshipone\",\"https:\\\/\\\/x.com\\\/theflagshipone\",\"https:\\\/\\\/www.instagram.com\\\/flagship_one\",\"https:\\\/\\\/www.youtube.com\\\/channel\\\/UC0oyKphffBM2qkJ-gKPmMXw\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#\\\/schema\\\/person\\\/a3cf463514bd03eb7656953ef8f75700\",\"name\":\"FlagshipOne\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g\",\"caption\":\"FlagshipOne\"},\"description\":\"The world's top supplier of programmed OEM (Original Equipment Manufacturer) Powertrain Control Modules (PCM), Engine Control Modules (ECM), Injection Control Modules (IDM), Body Control Modules (BCM), Transmission Control Modules (TCM), Engine Control Units and all other car control units. With over a decade in the business, we are the most reliable source when it comes to programming services for replacement engine control modules.\",\"sameAs\":[\"https:\\\/\\\/www.fs1inc.com\\\/\",\"https:\\\/\\\/www.facebook.com\\\/flagshipone\\\/\",\"https:\\\/\\\/www.instagram.com\\\/flagship_one\\\/\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/fs1inc\"],\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/author\\\/flagship1inc\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming & Faults - Flagship One Blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/","og_locale":"en_US","og_type":"article","og_title":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming & Faults - Flagship One Blog","og_description":"Diagnose and replace the PCM on your 2003 Pontiac Sunfire. Learn about module failure symptoms, installation steps, reprogramming requirements, and common fault codes that trigger replacement.","og_url":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/","og_site_name":"Flagship One Blog","article_publisher":"https:\/\/www.facebook.com\/flagshipone","article_author":"https:\/\/www.facebook.com\/flagshipone\/","article_published_time":"2026-07-17T21:54:06+00:00","article_modified_time":"2026-07-19T16:25:34+00:00","og_image":[{"width":677,"height":610,"url":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp","type":"image\/webp"}],"author":"FlagshipOne","twitter_card":"summary_large_image","twitter_creator":"@theflagshipone","twitter_site":"@theflagshipone","twitter_misc":{"Written by":"FlagshipOne","Est. reading time":"9 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#article","isPartOf":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/"},"author":{"name":"FlagshipOne","@id":"https:\/\/www.fs1inc.com\/blog\/#\/schema\/person\/a3cf463514bd03eb7656953ef8f75700"},"headline":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &#038; Faults","datePublished":"2026-07-17T21:54:06+00:00","dateModified":"2026-07-19T16:25:34+00:00","mainEntityOfPage":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/"},"wordCount":1894,"commentCount":0,"publisher":{"@id":"https:\/\/www.fs1inc.com\/blog\/#organization"},"image":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp","keywords":["2003","Pontiac","Sunfire"],"articleSection":["Car","Pontiac"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/","url":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/","name":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming & Faults - Flagship One Blog","isPartOf":{"@id":"https:\/\/www.fs1inc.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#primaryimage"},"image":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp","datePublished":"2026-07-17T21:54:06+00:00","dateModified":"2026-07-19T16:25:34+00:00","breadcrumb":{"@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#primaryimage","url":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp","contentUrl":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2026\/07\/2003-pontiac-sunfire-pcm-service-figure.webp","width":677,"height":610,"caption":"Figure from the factory control-module removal procedure for the 2003 Pontiac Sunfire"},{"@type":"BreadcrumbList","@id":"https:\/\/www.fs1inc.com\/blog\/2003-pontiac-sunfire-pcm-replacement-guide\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.fs1inc.com\/blog\/"},{"@type":"ListItem","position":2,"name":"2003 Pontiac Sunfire PCM: Replacement, Reprogramming &#038; Faults"}]},{"@type":"WebSite","@id":"https:\/\/www.fs1inc.com\/blog\/#website","url":"https:\/\/www.fs1inc.com\/blog\/","name":"Flagship One Blog","description":"Flagship One Inc. OEM Engine Computers  Control Modules","publisher":{"@id":"https:\/\/www.fs1inc.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.fs1inc.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.fs1inc.com\/blog\/#organization","name":"Flagship One, Inc.","url":"https:\/\/www.fs1inc.com\/blog\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fs1inc.com\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2019\/06\/web-lg-fs1-logo.png","contentUrl":"https:\/\/www.fs1inc.com\/blog\/wp-content\/uploads\/2019\/06\/web-lg-fs1-logo.png","width":1341,"height":1098,"caption":"Flagship One, Inc."},"image":{"@id":"https:\/\/www.fs1inc.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/flagshipone","https:\/\/x.com\/theflagshipone","https:\/\/www.instagram.com\/flagship_one","https:\/\/www.youtube.com\/channel\/UC0oyKphffBM2qkJ-gKPmMXw"]},{"@type":"Person","@id":"https:\/\/www.fs1inc.com\/blog\/#\/schema\/person\/a3cf463514bd03eb7656953ef8f75700","name":"FlagshipOne","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/351b81e51993825aea73280c48061a7205fdd2189730ebbdee5d63894c5cebb4?s=96&d=mm&r=g","caption":"FlagshipOne"},"description":"The world's top supplier of programmed OEM (Original Equipment Manufacturer) Powertrain Control Modules (PCM), Engine Control Modules (ECM), Injection Control Modules (IDM), Body Control Modules (BCM), Transmission Control Modules (TCM), Engine Control Units and all other car control units. With over a decade in the business, we are the most reliable source when it comes to programming services for replacement engine control modules.","sameAs":["https:\/\/www.fs1inc.com\/","https:\/\/www.facebook.com\/flagshipone\/","https:\/\/www.instagram.com\/flagship_one\/","https:\/\/www.linkedin.com\/company\/fs1inc"],"url":"https:\/\/www.fs1inc.com\/blog\/author\/flagship1inc\/"}]}},"_links":{"self":[{"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts\/534675","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/comments?post=534675"}],"version-history":[{"count":2,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts\/534675\/revisions"}],"predecessor-version":[{"id":538744,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts\/534675\/revisions\/538744"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/media\/526045"}],"wp:attachment":[{"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/media?parent=534675"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/categories?post=534675"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/tags?post=534675"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}