B2533

CIRCUIT DESCRIPTION
The fog lamp relay is controlled by the Body Control Module (BCM). Battery positive voltage is applied to the coil side of the fog lamp relay. The BCM grounds the fog lamp relay control circuit in order to turn on the fog lamp relay. When the fog lamp relay control circuit becomes shorted to battery positive voltage, DTC B2533 is set.

CONDITIONS FOR RUNNING THE DTC
^ The ignition switch is in the ON position.
^ The headlamp switch is in the HEAD or PARK position.

CONDITIONS FOR SETTING THE DTC
All of the following conditions must be met:
^ The ignition switch is in the ON position.
^ The headlamp switch is in the PARK or HEAD position.
^ The fog lamp relay control circuit is shorted to battery positive voltage for 250 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
^ DTC B2533 is stored in the BCM memory.
^ The fog lamps are inoperative when the headlamps or park lamps are on.

CONDITIONS FOR CLEARING THE DTC
^ The conditions for setting the DTC are no longer present.
^ A history DTC clears after 100 malfunction free ignition cycles.
^ The BCM receives the clear code command from the scan tool.

DIAGNOSTIC AIDS
^ The fog lamps will only illuminate under the following conditions:
- The park lamps or low beam headlamps are on.
- The highbeam headlamps are off.
- The fog lamp switch is in the on position.
^ If the DTC is a history DTC, the problem may be intermittent. Refer to Diagnostic Aids for Circuit Testing and Wiring Repair procedures.

TEST DESCRIPTION

Steps 1-3:

Steps 4-11:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the fog lamp relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Tests for voltage at the coil side of the fog lamp relay.
4. Verifies that the body control module is providing ground to the fog lamp relay.