1999 Chrysler LHS PCM/ECM Relearn & Replacement
The Powertrain Control Module and Engine Control Module in the 1999 Chrysler LHS manage fuel delivery, ignition timing, and transmission shifts. When they fail, the vehicle may exhibit stalling, poor acceleration, or misfire codes, disrupting drivability.
Quick Summary
- PCM relearn takes 0.5 hours, R&R 0.4 hours
- ECM relearn takes 0.5 hours, R&R 0.4 hours
- Reprogramming requires the vehicle’s VIN and mileage
- Speed control servo and bracket installed with fastener tightening
- Radio and clock are reprogrammed after battery reconnection
When your 1999 Chrysler LHS starts to misfire, stall, or lose power, the Powertrain Control Module or Engine Control Module could be the source. Understanding how these modules work, where they sit, and how to replace them can help you keep the vehicle running reliably. This guide explains the basics, shows the steps you’ll need to take, and highlights how Flagship One’s units simplify the process.
What the PCM Does in a 1999 Chrysler LHS
The Powertrain Control Module in the 1999 Chrysler LHS directs the engine’s fuel and ignition systems while coordinating transmission shifts. The Engine Control Module focuses on engine timing and sensor data. replacement engine computers for the 1999 Chrysler LHS ensures your vehicle’s performance remains consistent. Both modules must communicate correctly with other vehicle systems; any disruption can trigger misfire codes, stalling, or a loss of power. Properly functioning modules keep the 1999 Chrysler LHS running smoothly and safely.
Where the PCM Is Located and What Replacement Involves
The Powertrain Control Module is located behind the dashboard, accessible by removing the lower dash panel. Replacing it involves disconnecting the module’s power and ground connectors, removing the mounting bolts, and installing the new unit. The Engine Control Module sits in the engine bay, attached to the firewall. To replace it, you must remove the engine bay cover, disconnect the wiring harness, and swap the old module for the new one. Both replacements require the book times of 0.5 hours for relearn and 0.4 hours for removal and reinstallation, as noted in the labor facts.
How to Reach the PCM on the 1999 Chrysler LHS
- Remove speed control servo and bracket and reposition out of the way ei.
- Remove washer bottle filler neck.
- Remove Transmission Control Module (TCM) reposition out of the way.
- Remove PCM Disconnect PCM 2 40-way connector.
Work with the ignition off, and treat the module as static-sensitive: avoid touching the connector pins at any point.
| Operation | Configuration | Book Time |
|---|---|---|
| Powertrain Control Module Relearn | All configurations | 0.5 hr |
| Powertrain Control Module R&R | All configurations | 0.4 hr |
| Engine Control Module Relearn | All configurations | 0.5 hr |
| Engine Control Module R&R | All configurations | 0.4 hr |
Programming Requirements After Replacement
After installing a new PCM or ECM, the factory procedure calls for using the DRB scan tool to reprogram the unit with the vehicle’s original VIN and mileage, then reconnecting the negative battery cable, and reprogramming the radio and clock. Flagship One units arrive VIN-programmed, so those steps are already completed. You only need to connect the new module and verify communication with the scan tool. a VIN-programmed replacement unit simplifies the process and reduces labor.
Symptoms of a Failing PCM
Common symptoms of a failing PCM or ECM in the 1999 Chrysler LHS include stalling, misfires, poor acceleration, and erratic shifting. If the vehicle fails to start or displays a dead scan-tool communication, it may be due to a faulty module. Powertrain Control Module Failure can be one of the diagnostic trouble codes triggered by these issues, indicating that the module’s internal circuitry is not functioning correctly.
Module Trouble Codes on the 1999 Chrysler LHS
The following internal trouble codes are documented for the 1999 Chrysler LHS PCM and ECM: P0600, P0601, P0622, P0645, P1682, P1683, P1685, P1686, P1687, P1695, P1696, P1697, P1698.
| Code | Meaning | Full Guide |
|---|---|---|
| P0600 | Module-internal fault | Full P0600 guide → |
| P0601 | Internal memory checksum error | Full P0601 guide → |
| P0622 | Module-internal fault | Full P0622 guide → |
| P0645 | Module-internal fault | Full P0645 guide → |
| P1682 | Module-internal fault | Full P1682 guide → |
| P1683 | Control module fault | Full P1683 guide → |
| P1685 | Module-internal fault | — |
| P1686 | Module-internal fault | — |
| P1687 | Module-internal fault | — |
| P1695 | Module-internal fault | — |
| P1696 | Module-internal fault | — |
| P1697 | Module-internal fault | — |
Factory Service Bulletins Worth Knowing
The factory service bulletin #08-030-06 Rev. A addresses Powertrain Control Module Initialization for the 1999 Chrysler LHS. This bulletin provides guidance on correctly initializing the module during replacement or repair.
| Bulletin | Subject | What It Addresses |
|---|---|---|
| 08-030-06 Rev. A | 08-030-06 Rev. A Powertrain Control Module Initialization | — |
Protecting the PCM in Your 1999 Chrysler LHS
- Ensure the charging system remains healthy to prevent voltage spikes that can damage the PCM/ECM
- Keep all connector grounds clean and secure to maintain reliable communication
- Avoid jump‑starting the vehicle without proper precautions to prevent sudden voltage surges
- Address any diagnostic trouble codes promptly to avoid further module degradation
- Maintain connector seals to keep moisture and contaminants out of the module connections
Frequently Asked Questions
How long does it take to replace the PCM in a 1999 Chrysler LHS?
The labor book time for replacing the Powertrain Control Module in the 1999 Chrysler LHS is 0.4 hours, plus 0.5 hours for relearn if required. The total time depends on the shop’s workflow and any additional diagnostics.
Do I need to reprogram the radio after installing a new ECM?
Yes, after installing a new Engine Control Module, the factory procedure requires reprogramming the radio and clock. Flagship One units are pre‑programmed, so the radio reprogramming step is not necessary when using our replacement.
What codes might appear if the PCM fails in a 1999 Chrysler LHS?
Common PCM failure codes include P0600, P0601, and P0622. These indicate internal module faults and typically require module replacement or relearn procedures.
If you’re experiencing performance issues with your 1999 Chrysler LHS, you can choose between a repair that involves relearning modules or a refurbished replacement that comes pre‑programmed. Both options restore reliable operation, but a refurbished unit saves time and reduces the risk of incomplete reprogramming.
Flagship One stocks a refurbished, VIN-programmed PCM for the 1999 Chrysler LHS with a lifetime warranty, free shipping and no core charge. The full Chrysler LHS module lineup covers other engine configurations as well.
Final Thoughts
For the 1999 Chrysler LHS, a faulty Powertrain Control Module or Engine Control Module can lead to stalling, misfires, or shifting problems. By addressing these modules promptly, you can keep the vehicle operating smoothly. Consider a refurbished replacement for a hassle‑free solution.