PCM Reset

WARNING: This page does not describe the selected car, but rather 26 other vehicles, including the 1999 Mercury Tracer, 1999 Mercury Sable, 1999 Mercury Mystique, 1999 Mercury Mountaineer, and 1999 Mercury Grand Marquis. However, it is still accessible from the selected car via links, so may be relevant.

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 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 ODD-II DRIVE CYCLE. See DRIVE CYCLES 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.

CAUTION: When battery is disconnected, vehicle computer may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See appropriate model in COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting the battery.