PCM Reset Procedure
After a PCM reset procedure has been performed, the following conditions will be met
- All DTCs will be cleared from PCM memory.
- All freeze frame data will be cleared from PCM memory.
- Diagnostic monitoring results will be cleared from PCM memory.
- OBD-II system MONITOR & RECORD status will reset.
- DTC P1000 will be set in PCM memory until all OBD-II system monitors or components have been tested to satisfy OBD-II drive cycle without any faults occurring. To clear DTC P1000, perform «DRIVE CYCLE PROCEDURES»(ref-97420-S07146983132001050800000) under ADDITIONAL SYSTEM FUNCTIONS. Ensure OBD-II DRIVE CYCLE PROCEDURES are performed to verify repair.
To perform PCM reset using scan tool, follow scan tool manufacturer's operating instructions. If after clearing DTCs a problem has not been corrected, or a fault is still present, a hard code will immediately be reset in PCM memory.
| CAUTION | When battery is disconnected, vehicle computer may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting the battery. |
Keep Alive Random Access Memory (RAM) Reset Procedure
- Resetting keep alive RAM will return PCM memory to its default setting. Adaptive learning contents such as idle and fuel trim are included. PCM reset procedure is part of keep alive RAM reset. See «PCM Reset Procedure»(ref-97420-S07226667802001050800000) . If an error message is received or scan tool is unable to perform keep alive RAM reset procedure, disconnect negative battery terminal for a minimum for 5 minutes, then go to next step. If using Worldwide Diagnostic System (WDS) or New Generation Star (NGS) scan tool, turn ignition switch to ON position. Select ACTIVE COMMAND MODES, then select RESET KEEP ALIVE MEMORY. Go to next step.
- After keep alive RAM has been reset, engine must idle for 15 minutes to learn new idle air trim values. Idle quality will improve as strategy adapts. Adaptation occurs in 4 separate modes. See «IDLE AIR TRIM LEARNING MODES»(ref-97420-S15662465722001011100000) table. IDLE AIR TRIM LEARNING MODES Transmission Gear Selector Position A/C Mode Neutral On Neutral Off Drive On Drive Off