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Engine Controls - Self-Diagnostics: Maintenance Mazda 626 GF

PCM Reset

After a PCM reset procedure has been performed, the following conditions will be met

  1. All DTCs will be cleared from PCM memory.
  2. All freeze frame data will be cleared from PCM memory.
  3. Diagnostic monitoring results will be cleared from PCM memory.
  4. OBD-II system monitor status will reset.
  5. 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 OBD-II DRIVE CYCLE. See «DRIVE CYCLES»(ref-91102-S24383971062001030200000) under ADDITIONAL SYSTEM FUNCTIONS.

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 fault is still present, hard code will immediately be reset in PCM memory.

CAUTIONWhen 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.

Resetting Keep-Alive Memory (KAM)

  1. Resetting KAM will return PCM memory to its default setting. If not using a scan tool, disconnect negative battery terminal for a minimum for 5 minutes then go to next step. If using New Generation Star (NGS) scan tool, turn ignition on. Select ACTIVE COMMAND MODES, then RESET KEEP ALIVE MEMORY. Go to next step.
  2. After KAM 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 with engine idling, transmission selector and A/C in specified position. See «IDLE AIR TRIM LEARNING MODES»(ref-91102-S29504596562001030200000) table. IDLE AIR TRIM LEARNING MODES Transmission Gear Selector Position A/C Mode Neutral On Neutral Off Drive On Drive Off