Circuit Description
The body control module (BCM) turns on the auto park lamp control 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 LAMP 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 B2585 Park Lamp Control Circuit
Conditions for Running the DTC
| • | The ignition switch is in the ON position. |
| • | The ambient light sensor senses a dark condition (automatic lamp control (ALC) park lamps on). |
Conditions for Setting the DTC
| • | The park lamp relay control circuit is open or shorted to voltage for 5 seconds. |
| • | The park lamp supply voltage circuit is open or shorted to ground for 5 seconds. |
Action Taken When the DTC Sets
The SERVICE indicator will illuminate.
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
If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Listen for an audible click when the park lamp relay operates. Command both the ON and OFF states. Repeat the commands, as necessary.
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Tests for voltage at the coil side of the park lamp relay . The PARK LAMP fuse supplies battery positive voltage to the coil side of the park lamp relay.
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Verifies that the BCM is providing ground to the park lamp relay.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Exterior Lights Schematics | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the park ramp relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 9 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 5 | Go to Step 6 | |
5 | Test for an open or high resistance in the park lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 7 |
6 | Test for an open, high resistance, or short to voltage in the control circuit of the park lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 8 |
7 | Inspect for poor connection at the park lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 10 |
8 | Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 11 |
9 | Repair an open, high resistance, or short to ground in the coil side battery positive voltage circuit of the park lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | -- |
10 | Replace the park lamp relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 12 | -- |
11 | Replace the body control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. Did you complete the replacement? | Go to Step 12 | -- |
12 |
Does the DTC reset? | Go to Step 2 | -- |
