B1374

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
Circuit 439 is the ignition 1 positive voltage circuit input to the body control module (BCM) from the ignition switch. When the BCM senses that ignition is open, DTC B1372 is set.

CONDITIONS FOR RUNNING THE DTC
^ The engine is on.
^ At least 20 seconds has elapsed since the engine was started.

CONDITIONS FOR SETTING THE DTC
The ignition 1 input is inactive after the engine has been running for 20 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The SERVICE VEHICLE SOON indicator illuminates.
^ The check gauges chime sounds.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC B1372 will clear when the code setting condition is no longer present and the ignition switch is cycled.
^ All BCM history codes will clear after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles.

DIAGNOSTIC AIDS
If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while wiggling the wiring and connectors. This can often cause the malfunction to appear.

TEST DESCRIPTION
The numbers listed below refer to the numbers on the diagnostic table.
4. This step determines if CKT 439 is shorted to ground.
5. This step determines if the BCM is internally shorted.
6. This step determines if voltage is supplied from the battery to the A/C BFC fuse.