P052

DTC P052/P109:

PCM Power And Ground Circuit:

CIRCUIT DESCRIPTION:
This diagnostic test monitors the PCM's keep alive memory for a loss or unintended change of data. If such a condition occurs, Code P052/P109 will set.

TEST CONDITION(S):
Test continuously.

FAILURE CONDITION(S):
Keep alive memory checksum does not match previous checksum.

ACTION TAKEN:
None.

NOTES ON INTERMITTENTS:
If the battery has been disconnected for any reason Code P052/P109 will set.

The PCM keeps a running check on the memory; if memory changes it resets.

Code P052/P109 may set while keying "OFF" in diagnostics. If the BCM is sending new information to the PCM when the ignition is turned "OFF," the PCM may think it has been switched, causing a reset.