CONTINUOUS MEMORY CODES
These codes are retained in memory for usually around 50 warm-up cycles. To clear the codes for the purposes of testing or confirming repair, perform the code reading procedure. Use the DRB-II scan tool or equivalent to erase the memory. Disconnecting the negative battery cable will not erase the code completely from the memory, it will remain as a continuous fault. The MIL lamp will remain out if you disconnect the battery, and the malfunction that lit the MIL lamp is repaired. After 50 warm-up cycles or so are reached, the code will be erased from the ECM's memory.
KEEP ALIVE MEMORY
The Keep Alive Memory (KAM) contains the adaptive factors used by the processor to compensate for component tolerances and wear. It should not be routinely cleared during diagnosis. If an emissions related part is replaced during repair, the KAM must be cleared. Failure to clear the KAM may cause severe driveability problems since the correction factor for the old component will be applied to the new component.
To clear the Keep Alive Memory, disconnect the negative battery cable for at least 5 minutes. After the memory is cleared and the battery reconnected, the vehicle must be driven at least 10 miles so that the processor may relearn the needed correction factors. The distance to be driven depends on the engine and vehicle, but all drives should include steady-throttle cruise on open roads. Certain driveability problems may be noted during the drive because the adaptive factors are not yet functioning.