B0286
B0286 - Electric Rear Defog Circuit HighSchematic:
CIRCUIT DESCRIPTION
When rear defog request is active, the BCM will respond by grounding circuit 193, the coil side of the rear defog relay.
This action energizes the rear defog relay.
The first time in an ignition cycle that the rear defog is activated, the rear defog will remain On for 15 minutes or until the ignition switch is turned Off. If rear defog is activated again during the same ignition cycle, rear defog will remain On for 7 1/2 minutes or until the ignition switch is turned Off.
DTC PARAMETERS
^ Ignition in RUN
^ Circuit 193 is shorted to battery voltage
^ BCM is commanding the rear defog system to the ON state
^ No light will illuminate in the I/P.
DIAGNOSTIC AIDS :
^ When a shorted to battery voltage condition exists in circuit 193 and the BCM has been requested to activate the rear defog system, the BCM will attempt to switch the circuit 193 to ground. High current flow will result and the BCM output will go into a protective state. The BCM output will not allow itself to be activated for as much as 3 minutes.
^ 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.
^ Several lamps flash on I/P with the ignition Off.
^ Check for poor connection at the ECM. 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).
TEST
Diagnostic Chart:
