B0285

Schematic:

CIRCUIT DESCRIPTION
When rear defog request is active, the BCM will respond by grounding circuit 193, the coil of the rear defog relay. This action energizes the rear defrost relay.

The first time in an ignition cycle that the rear defrost is activated, rear defrost will remain "ON" for 15 minutes or until the ignition switch is turned "OFF." If rear defrost is activated again during the same ignition cycle, rear defrost will remain "ON" for 7 1/2 minutes or until the ignition switch is turned "OFF."

DTC PARAMETERS
^ Ignition in RUN
^ Circuit 193 grounded or open
^ BCM is NOT requesting the rear defrost system
^ Condition exists for 30 seconds

DIAGNOSTIC AIDS:
^ Check for poor connection at the BCM. Inspect harness connectors for backed out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals and poor terminal to wire connection (terminal crimped over wire insulation and not conductors).
^ Inspect wiring harness for damage. Check for broken or chaffed insulation.
^ If fault is suspected to be intermittent, wiggling harness wiring may help in locating fault.

TEST

Diagnostic Chart 5: