B2587

DTC B2587

CIRCUIT DESCRIPTION
The body control module (BCM) turns ON the park lamp relay when the ambient light sensor senses a dark condition. Battery positive voltage is supplied to the park lamp relay at all times through the PARK fuse. The BCM grounds the park lamp relay control circuit in order to activate the relay.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B2587 Park Lamp Control Circuit Low

CONDITIONS FOR RUNNING THE DTC
- The ignition switch is in the RUN position.
- The headlamp switch is in the AUTO position.
- The ambient light sensor senses a light condition, automatic lamp control (ALC) is commanding the park lamps OFF.

CONDITIONS FOR SETTING THE DTC
The following condition will set this DTC:
The park lamp relay control circuit is shorted to ground or open for 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The park lamps will remain illuminated if shorted to ground.
- The park lamps will not illuminate if open.

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

DIAGNOSTIC AIDS
If the DTC is a history DTC, the problem may be intermittent.

TEST DESCRIPTION

Step 1 - Step 13:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the park 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 park lamp relay. The PARK fuse supplies battery positive voltage to the coil side of the park lamp relay