Circuit Description
When the rear defog request is active, the body control module (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, the
rear defrost will remain ON for 15 minutes or until the ignition is turned
OFF. If the rear defrost is activated again during the same ignition cycle, the
rear defrost will remain ON for 7 ½ minutes or until the ignition
is turned OFF.
Conditions for Setting the DTC
| • | The ignition is in RUN. |
| • | The circuit 193 is grounded or open. |
| • | The BCM is NOT requesting the rear defrost system. |
| • | The condition exists for 30 seconds, output OFF. |
| • | No light will illuminate in the instrument panel (I/P). |
Diagnostic Aids
| • | Inspect for a poor connection at the BCM. Inspect the 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 the wiring harness for damage. Inspect for broken or chaffed insulation. |
| • | If a fault is suspected to be intermittent, wiggling the harness wiring
may help in locating the fault. |
| • | The LED on the defogger button does not illuminate when pressed. |
