{"id":530220,"date":"2026-07-17T09:42:17","date_gmt":"2026-07-17T13:42:17","guid":{"rendered":"https:\/\/www.fs1inc.com\/blog\/?p=530220"},"modified":"2026-07-19T11:40:47","modified_gmt":"2026-07-19T15:40:47","slug":"1999-gmc-jimmy-pcm-replacement-guide","status":"publish","type":"post","link":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/","title":{"rendered":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide"},"content":{"rendered":"<div class=\"container\">\n<section class=\"hero\">\n<div class=\"code-badge\">PCM<\/div>\n<h1>1999 GMC Jimmy PCM ECM Replacement and Programming Guide<\/h1>\n<p class=\"hero-subtitle\">The Powertrain Control Module (PCM) and Engine Control Module (ECM) on your 1999 GMC Jimmy are the central computers that manage fuel injection, ignition timing, emissions controls, and transmission shifting. When these units fail internally, your vehicle may not start, run poorly, or set diagnostic codes.<\/p>\n<\/section>\n<div class=\"quick-summary\">\n<h2>Quick Summary<\/h2>\n<ul>\n<li>The 1999 GMC Jimmy uses either a PCM or ECM depending on configuration, controlling the 4.3L V6 engine and transmission<\/li>\n<li>Internal module failures produce codes P0601-P0605 and P1621-P1631, indicating EEPROM or processor faults<\/li>\n<li>Replacement requires accessing the module under the hood or instrument panel, with labor ranging from 1.0 to 1.8 hours<\/li>\n<li>After replacement, a relearn procedure is required to calibrate the new module to your vehicle&#8217;s sensors<\/li>\n<li>Flagship One sells VIN-programmed replacement units that arrive ready to install<\/li>\n<\/ul>\n<\/div>\n<div class=\"info-section\">\n<p>If your 1999 GMC Jimmy runs poorly, won&#8217;t start, or your scan tool can&#8217;t communicate with the engine computer, the PCM or ECM may be the culprit. These modules are the brain of your vehicle&#8217;s powertrain, and internal failures are surprisingly common as vehicles age. This guide walks you through recognizing module failure symptoms, understanding labor requirements for replacement, and knowing what programming steps follow installation. Whether you diagnose the problem yourself or leave it to a shop, understanding the process helps you make informed decisions about repairing your Jimmy.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>What the PCM Does in a 1999 GMC Jimmy<\/h2>\n<p>The PCM (Powertrain Control Module) on your 1999 GMC Jimmy serves as the primary computer for the 4.3L V6 engine and automatic transmission. It processes input from dozens of sensors and outputs commands to fuel injectors, ignition coils, the torque converter clutch, and emissions components. The ECM (Engine Control Module) handles engine-focused functions in some configurations. Both modules maintain calibration data in non-volatile memory, and when this internal memory fails, the module can no longer control the engine properly. Replacing the module requires installing a <a href=\"https:\/\/www.fs1inc.com\/gm\/gmc-pcm-ecm-ecu-engine-computer\/jimmy-engine-computers.html\">replacement PCMs for the Jimmy<\/a> that matches your vehicle&#8217;s VIN and configuration. Without a functioning PCM or ECM, your Jimmy cannot run \u2014 the engine may crank but not start, or may stall immediately after starting.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Where the PCM Is Located and What Replacement Involves<\/h2>\n<p>The PCM or ECM on a 1999 GMC Jimmy is located either under the hood (near the firewall on the driver&#8217;s side) or behind the instrument panel on the passenger side. Access method determines labor time: under-hood replacement requires 1.0 book hours, while instrument-panel access requires 1.8 hours due to dashboard disassembly. The factory cautions against touching connector pins or soldered components during any internal work to prevent electrostatic discharge damage to the PCM. When replacing, ensure the connector is clean and sealed, and torque any specified fasteners to factory standards. Plan for additional time if diagnostic verification is needed before and after the R&amp;R procedure.<\/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\">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\">Powertrain Control Module R&amp;R<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Under Hood<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">1.0 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\">Under Inst. Panel<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">1.8 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\">Engine 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\">Engine Control Module R&amp;R<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Under Hood<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">1.0 hr<\/td>\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\">Under Inst. Panel<\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">1.8 hr<\/td>\n<\/tr>\n<\/table>\n<\/div>\n<div class=\"info-section\">\n<h2>Programming Requirements After Replacement<\/h2>\n<p>After replacing the PCM or ECM on your 1999 GMC Jimmy, the factory procedure requires a relearn process to calibrate the new module to your vehicle&#8217;s specific sensors and idle characteristics. The PCM Relearn procedure takes 0.5 hours, and if an ECM is separately programmed, that relearn adds another 0.5 hours. This step is essential for proper drivability. Flagship One units arrive VIN-programmed to your specific vehicle, meaning the calibration data is pre-loaded before shipping. This eliminates the need for you to perform the relearn procedure yourself or pay a dealer to program the replacement \u2014 the module is ready to install and start your engine.<\/p>\n<p>Every <a href=\"https:\/\/www.fs1inc.com\/1999-gmc-jimmy-4-3l-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 PCM or ECM fails internally on your 1999 GMC Jimmy, common symptoms include a no-start condition where the engine cranks but won&#8217;t fire, intermittent stalling, and rough idle. You may notice multiple misfire codes setting simultaneously, or your scan tool may fail to communicate with the module entirely. Transmission shifting may become erratic or the vehicle may default to limp mode. In some cases, the engine starts but runs poorly with hesitation under acceleration. If your Jimmy displays any of these symptoms and standard sensor tests check out, the module itself is a likely suspect. A code like <a href=\"https:\/\/www.fs1inc.com\/blog\/dtc-p0601-internal-control-module-memory-checksum-error\/\">internal memory failure<\/a> indicates the PCM&#8217;s internal memory checksum is invalid, pointing directly to module internal failure rather than an external wiring issue.<\/p>\n<\/div>\n<div class=\"info-section\">\n<h2>Module Trouble Codes on the 1999 GMC Jimmy<\/h2>\n<p>Your 1999 GMC Jimmy may store module-internal trouble codes when the PCM or ECM fails. These codes (P0601 through P0605 for general processor\/memory faults, plus P1621, P1626, and P1631 for theft-related calibration losses) indicate problems internal to the control module itself rather than sensor or wiring failures. When these codes appear after verifying external connections are sound, module replacement is the indicated repair.<\/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-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\"><b>P1626<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Module-internal fault<\/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>P1631<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Module-internal fault<\/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>Factory Service Bulletins Worth Knowing<\/h2>\n<p>Factory service bulletins address PCM service for your 1999 GMC Jimmy. Bulletin #99-06-04-053 covers PCM reprogramming procedures. Bulletin #83-81-32 introduced new PCM connector service kits to address wiring harness issues. Bulletin #02-06-04-057E provides warranty labor operation assignments for control module reprogramming work. These bulletins confirm that PCM repair and replacement procedures are well-established for this model year.<\/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\"><b>99-06-04-053<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">Info &#8211; PCM Reprogramming &#8211; (Oct 26, 1999)<\/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>83-81-32<\/b><\/td>\n<td style=\"border:1px solid #d6dbe3;padding:9px 12px\">INFO &#8211; NEW PCM CONNECTOR SERVICE KITS &#8211; (Sep 16, 1998)<\/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>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 1999 GMC Jimmy<\/h2>\n<ul style=\"margin:14px 0 6px 0;padding-left:26px\">\n<li style=\"margin:10px 0;line-height:1.65\">Maintain healthy charging system voltage \u2014 a weak alternator or failing battery stresses the PCM&#8217;s power supply<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Keep all ground connections clean and tight, especially the main engine and chassis grounds<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Avoid jump-starting other vehicles \u2014 voltage spikes can damage the PCM&#8217;s internal circuits<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Address check-engine lights promptly \u2014 driving with active codes can mask underlying module issues<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Inspect engine-bay connectors periodically for corrosion, water intrusion, or damaged seals<\/li>\n<li style=\"margin:10px 0;line-height:1.65\">Store your Jimmy in a temperature-stable environment when possible to reduce thermal cycling stress<\/li>\n<\/ul>\n<\/div>\n<div class=\"info-section\">\n<h2>Frequently Asked Questions<\/h2>\n<h3>Can I swap a used PCM from another 1999 GMC Jimmy into my vehicle?<\/h3>\n<p>A used PCM must be programmed to your specific vehicle&#8217;s VIN and calibration to function properly. Without proper programming, the engine may not start or will run poorly. Dealer programming or a VIN-programmed replacement unit is required.<\/p>\n<h3>My 1999 GMC Jimmy cranks but won&#8217;t start \u2014 could this be the PCM?<\/h3>\n<p>Yes, a failed PCM can cause a no-start condition even when the engine cranks normally. However, other causes like failed crankshaft position sensors, fuel pump issues, or ignition failures can produce similar symptoms. Proper diagnosis is recommended before replacing the module.<\/p>\n<h3>How long does it take to replace the PCM on a 1999 GMC Jimmy?<\/h3>\n<p>Labor time ranges from 1.0 hour for under-hood replacement to 1.8 hours if the module is located behind the instrument panel. Add 0.5 to 1.0 hour for relearn procedures after installation if not using a pre-programmed unit.<\/p>\n<\/div>\n<div class=\"info-section\">\n<p>When your 1999 GMC Jimmy&#8217;s PCM or ECM fails, you have two primary repair paths. You may choose a new or refurbished replacement unit from a supplier like Flagship One that arrives VIN-programmed and ready to install. Alternatively, some salvage yards offer used modules, but you must account for programming costs and potential compatibility issues. For the best outcome, verify the module is matched to your specific engine and transmission configuration before purchasing.<\/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\/gmtypeO\/gm-pcm-typeo-1.jpg\" alt=\"Refurbished VIN-programmed PCM for the 1999 GMC Jimmy\" loading=\"lazy\"\/><figcaption style=\"font-size:13px;color:#667085;margin-top:8px\">A refurbished, VIN-programmed replacement PCM for the 1999 GMC Jimmy from Flagship One.<\/figcaption><\/figure>\n<p>Flagship One stocks a <a href=\"https:\/\/www.fs1inc.com\/1999-gmc-jimmy-4-3l-engine-computer-pcm-ecm-ecu-programmed-plug-play.html\"><b>refurbished, VIN-programmed PCM for the 1999 GMC Jimmy<\/b><\/a> with a lifetime warranty, free shipping and no core charge. The full <a href=\"https:\/\/www.fs1inc.com\/gm\/gmc-pcm-ecm-ecu-engine-computer\/jimmy-engine-computers.html\">GMC Jimmy 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 PCM and ECM are essential computers in your 1999 GMC Jimmy, and internal failures can leave you stranded. Understanding the symptoms, labor requirements, and programming needs helps you approach the repair with confidence. Whether you handle the installation yourself or trust a professional, sourcing a properly programmed replacement module is the key to getting your Jimmy back on the road.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Diagnose and replace the PCM or ECM on your 1999 GMC Jimmy with 4.3L V6. Includes symptoms, labor times, programming requirements, and factory cautions.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"elementor_header_footer","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[258,270],"tags":[52,68,994],"class_list":["post-530220","post","type-post","status-publish","format-standard","hentry","category-car","category-gmc","tag-52","tag-gmc","tag-jimmy"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.0 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>1999 GMC Jimmy PCM ECM Replacement and Programming Guide - 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\/1999-gmc-jimmy-pcm-replacement-guide\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"1999 GMC Jimmy PCM ECM Replacement and Programming Guide - Flagship One Blog\" \/>\n<meta property=\"og:description\" content=\"Diagnose and replace the PCM or ECM on your 1999 GMC Jimmy with 4.3L V6. Includes symptoms, labor times, programming requirements, and factory cautions.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-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=\"2026-07-17T13:42:17+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-07-19T15:40:47+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg\" \/>\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=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/\"},\"author\":{\"name\":\"FlagshipOne\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#\\\/schema\\\/person\\\/a3cf463514bd03eb7656953ef8f75700\"},\"headline\":\"1999 GMC Jimmy PCM ECM Replacement and Programming Guide\",\"datePublished\":\"2026-07-17T13:42:17+00:00\",\"dateModified\":\"2026-07-19T15:40:47+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/\"},\"wordCount\":1452,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/media\\\/wysiwyg\\\/googleshop\\\/gmtypeO\\\/gm-pcm-typeo-1.jpg\",\"keywords\":[\"1999\",\"GMC\",\"jimmy\"],\"articleSection\":[\"Car\",\"GMC\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/\",\"name\":\"1999 GMC Jimmy PCM ECM Replacement and Programming Guide - Flagship One Blog\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/media\\\/wysiwyg\\\/googleshop\\\/gmtypeO\\\/gm-pcm-typeo-1.jpg\",\"datePublished\":\"2026-07-17T13:42:17+00:00\",\"dateModified\":\"2026-07-19T15:40:47+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.fs1inc.com\\\/media\\\/wysiwyg\\\/googleshop\\\/gmtypeO\\\/gm-pcm-typeo-1.jpg\",\"contentUrl\":\"https:\\\/\\\/www.fs1inc.com\\\/media\\\/wysiwyg\\\/googleshop\\\/gmtypeO\\\/gm-pcm-typeo-1.jpg\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/1999-gmc-jimmy-pcm-replacement-guide\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.fs1inc.com\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"1999 GMC Jimmy PCM ECM Replacement and Programming Guide\"}]},{\"@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":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide - 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\/1999-gmc-jimmy-pcm-replacement-guide\/","og_locale":"en_US","og_type":"article","og_title":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide - Flagship One Blog","og_description":"Diagnose and replace the PCM or ECM on your 1999 GMC Jimmy with 4.3L V6. Includes symptoms, labor times, programming requirements, and factory cautions.","og_url":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-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":"2026-07-17T13:42:17+00:00","article_modified_time":"2026-07-19T15:40:47+00:00","og_image":[{"url":"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg","type":"","width":"","height":""}],"author":"FlagshipOne","twitter_card":"summary_large_image","twitter_creator":"@theflagshipone","twitter_site":"@theflagshipone","twitter_misc":{"Written by":"FlagshipOne","Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#article","isPartOf":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/"},"author":{"name":"FlagshipOne","@id":"https:\/\/www.fs1inc.com\/blog\/#\/schema\/person\/a3cf463514bd03eb7656953ef8f75700"},"headline":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide","datePublished":"2026-07-17T13:42:17+00:00","dateModified":"2026-07-19T15:40:47+00:00","mainEntityOfPage":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/"},"wordCount":1452,"commentCount":0,"publisher":{"@id":"https:\/\/www.fs1inc.com\/blog\/#organization"},"image":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg","keywords":["1999","GMC","jimmy"],"articleSection":["Car","GMC"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/","url":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/","name":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide - Flagship One Blog","isPartOf":{"@id":"https:\/\/www.fs1inc.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#primaryimage"},"image":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#primaryimage"},"thumbnailUrl":"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg","datePublished":"2026-07-17T13:42:17+00:00","dateModified":"2026-07-19T15:40:47+00:00","breadcrumb":{"@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#primaryimage","url":"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg","contentUrl":"https:\/\/www.fs1inc.com\/media\/wysiwyg\/googleshop\/gmtypeO\/gm-pcm-typeo-1.jpg"},{"@type":"BreadcrumbList","@id":"https:\/\/www.fs1inc.com\/blog\/1999-gmc-jimmy-pcm-replacement-guide\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.fs1inc.com\/blog\/"},{"@type":"ListItem","position":2,"name":"1999 GMC Jimmy PCM ECM Replacement and Programming Guide"}]},{"@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\/530220","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=530220"}],"version-history":[{"count":2,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts\/530220\/revisions"}],"predecessor-version":[{"id":538175,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/posts\/530220\/revisions\/538175"}],"wp:attachment":[{"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/media?parent=530220"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/categories?post=530220"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fs1inc.com\/blog\/wp-json\/wp\/v2\/tags?post=530220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}