DTC B1652: Loss Of Keep Alive Memory (KAM): Description

Microprocessor calculates check sum on areas of memory that hold critical operation data at regular intervals (periodic check sum). Microprocessor also calculates check sum on memory locations when new data is written (running check sum). The microprocessor compares periodic check sum to running check sum. If they do not match, DTC is set.

When DTC is set, microprocessor will operate from preset critical operating data until new data is learned and stored in KAM.

DTC will clear when microprocessor calculates a successful comparison between periodic check sum and running check sum.