Circuit Description
The body control module (BCM) turns on the PARK LAMP relay when the ambient light sensor senses a dark condition or the park lamps are requested ON. Battery positive voltage is supplied to the PARK LAMP relay at all times. 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
B2585.01
This DTC will set if there is a short to voltage in the park lamp relay control circuit.
B2585.06
This DTC will set if there is an open or short to ground in the park lamp relay control circuit.
Action Taken When the DTC Sets
| • | The SERVICE indicator will illuminate. |
| • | The check gages chime sounds. |
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 .
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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This step tests for voltage at the coil side of the PARK LAMP relay .
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This step verifies that the BCM is providing ground to the PARK LAMP relay.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Exterior Lights Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
Does the PARK LAMP relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | |
3 | Is DTC B2585.01 set? | Go to Step 6 | Go to Step 4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 11 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 7 | Go to Step 8 | |
6 | Test the control circuit of the PARK LAMP relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
7 | Test for an open or high resistance in the park lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
8 | 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 . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 |
9 | Inspect for poor connection at the PARK LAMP relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
10 | 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 . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
11 | 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 . Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the PARK LAMP relay. Did you complete the replacement? | Go to Step 14 | -- |
13 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 |
Does the DTC reset? | Go to Step 2 | -- |
