DTC B1652: Loss Of Keep Alive Memory: Description

Control module calculates check sum on areas of memory that hold critical operation data at regular intervals (periodic check sum). Control module also calculates check sum on memory locations when new data is written (running check sum). Control module compares periodic check sum to running check sum. If they do not match, DTC is stored. When DTC is stored, control module will operate from preset critical operating data until new data is learned and stored in keep alive memory. A current DTC clears when malfunction no longer exists. A history DTC clears when module ignition cycle counter reaches reset threshold, without repeat of malfunction.