B1652 - HVAC Systems - Automatic

Diagnostic Trouble Code Chart:

Wiring Schematic:

CIRCUIT DESCRIPTION
The module contains a data storage area which can save pertinent data when the ignition is turned off. The Keep Alive Memory (KAM) data is lost if battery power is removed from the module. The KAM area is an integral part of the microprocessor and cannot be serviced separately.

CONDITIONS FOR SETTING THE DTC
DTC B1652 indicates that the keep alive, or long-term, memory in the module has been reset. It is a normal occurrence whenever power or ground is removed from the module, such as battery disconnected and reconnected.

ACTION TAKEN WHEN THE DTC SETS
Module KAM memory resets to initial values.

CONDITIONS FOR CLEARING THE DTC
^ This DTC requires an ignition cycle in order to change from current to history.
^ The DTC clears if the module no longer detects a KAM failure (check sum error).
^ A history DTC clears after 50 consecutive ignition cycles if the condition for the malfunction is no longer present.
^ The DTC may be cleared using a Scan TooL
^ The DTC may be cleared using the On-Board clearing DTCs feature.

DIAGNOSTIC AIDS
If DTC B1652 sets without a battery disconnect, ensure good terminal contacts at power feed CKT 840 (ORN) at connector C1 and ground CKT 341 (BRN) at connector C2. It power and ground are OK, replace the HCM.

TEST DESCRIPTION
2. Ensures that the DTC was not set in error.