B2527

CIRCUIT DESCRIPTION
The FOG LPS 15 A fuse in the engine wiring harness junction block supplies battery positive voltage to the fog lamp relay switch in the engine wiring harness junction block. The headlamp switch supplies battery positive voltage to the fog lamp relay coil. With the headlamp switch in either the park or headlamp position, and the fog lamp switch pressed, the body control module (BCM) will ground the fog lamp relay control circuit. The current flow is from the fog lamp relay to both front fog lamps and to ground G100.

If the driver selects high beam headlights, a high beam input is sent to the BCM by the dimmer switch. In response to this input the BCM de-energizes the fog lamp relay.

CONDITIONS FOR RUNNING THE DTC
^ The battery voltage between 9.0 and 16.0 volts.
^ The ignition switch in the RUN position.

CONDITIONS FOR SETTING THE DTC
When the front fog lamp switch signal circuit is shorted to ground for approximately 3 minutes.

ACTION TAKEN WHEN THE DTC SETS
The fog lamps will not operate.

CONDITIONS FOR CLEARING THE DTC
^ This DTC will clear the current status after the condition for setting the fault is corrected.
^ A history DTC will clear after 100 consecutive ignition cycles without a fault present.
^ A clear codes message is sent by the scan tool.

DIAGNOSTIC AIDS
^ Test the fog lamp switch for sticking in the ON position.
^ Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-8:

The number(s) below refer to the step number(s) on the diagnostic table.
2. OFF is the normal state of the switch before activation.
4. OFF is the normal state of the switch before activation.
5. This step tests for a short to ground on the front fog lamp switch signal circuit.
6. After replacement of the BCM you must calibrate the new module for proper operation.