Circuit Description
This is a trouble code (both current and history) that indicates the parklamps were not ON when the Automatic Lighting Control (ALC) relay output was ON.
Conditions for Setting the DTC
Meet all of the following conditions:
| • | The ALC option is enabled and ignition 1 is active. |
| • | The ALC parklamp relay output is active. |
| • | The parklamp input is not active for 5 seconds. |
Action Taken When the DTC Sets
| • | Stores the DTC B2585 in the body control module (BCM) memory. |
| • | The SERVICE VEHICLE SOON indicator will illuminate. |
| • | The check gauges chime sounds. |
Conditions for Clearing the DTC
| • | The body control module (BCM) reads the proper parklamp voltage. |
| • | Conditions for the fault are no longer present. |
| • | All the BCM history codes will be cleared after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles. |
| • | Use the Scan Tool scan tool. |
Diagnostic Aids
| • | If you find B+ on the BCM parklamp relay output, check the ALC parklamp relay and the power to the relay. |
| • | If the DTC is a history DTC, the problem may be intermittent. Try performing the above tests while wiggling the wiring and connectors. This can often cause the malfunction to appear. |
Step | Action | Yes | No |
|---|---|---|---|
|
Important: A short to ground will cause an open fuse(s). Before performing this diagnostic procedure, inspect the fuse(s) for an open. | |||
1 | Was the body control module (BCM) System Check performed? | Go to Step 2 | Go to the Body Control Module System Check |
2 | Are there any other ALC DTCs showing? | Go to the other ALC DTC table first | Go to Step 3 |
3 |
Does the PARK LAMP INPUT indicate Applied? | Go to Intermittents and Poor Connections Diagnosis in Wiring Systems | Go to Step 4 |
4 | Are the park lamps illuminated? | Go to Step 7 | Go to Step 5 |
5 |
Does the test lamp illuminate? | Go to Step 6 | Go to Step 10 |
6 |
Does the PARK LAMP INPUT indicate Applied? | Go to Step 8 | Go to Step 7 |
7 | Test for an open, high resistance, or short to ground in the park lamp voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at the Automatic Lamp Control Park Lamp Relay. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the BCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
10 | Repair an open, high resistance, or short to ground in the switch side battery positive voltage circuit of the Automatic Lamp Control Park Lamp Relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | -- |
11 | Replace the Automatic Lamp Control Park Lamp Relay. Did you complete the replacement? | Go to Step 13 | -- |
12 | Replace the BCM. Refer to Body Control Module Replacement . Is the repair complete? | Go to Step 13 | -- |
13 | Clear the DTCs from the memory. Are the DTCs cleared from the memory? | Go to the Body Control Module System Check | -- |
