PCM Reset Procedure
PCM reset procedure is used to clear codes. Scan tool is necessary to clear codes. When codes are cleared, freeze frame data, diagnostic monitoring test results, and system monitors are also reset. Follow scan tool equipment manufacturer's instructions to perform this function. If codes are cleared without satisfactorily performing identified drive cycle, DTC P1000 will set. 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 .
KEEP ALIVE RAM RESET PROCEDURE
| 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 battery. |
PCM adaptive memory Keep Alive Random Access Memory (RAM) restores default settings for idle, fuel trim and other PCM controlled systems. When Keep Alive RAM is reset, vehicle may exhibit some undesirable driveability characteristics until PCM relearns necessary values for optimum driveability. Manufacturer recommends using scan tool to restore default setting for Keep Alive RAM. Follow scan tool equipment manufacturers instructions to perform this function. If scan tool does not support this function, disconnect negative battery cable for a minimum of 5 minutes as an alternative Keep Alive RAM resetting procedure.