For a full page schematic, refer to
Park Lamps Control
in Body Control
Module Schematics.
Circuit Description
The body control module (BCM) monitors the voltage on CKT 2409 in order to determine the actual state of the park lamp relay. The BCM also uses CKT 1080 in order to energize the park lamp relay.
Conditions for Setting the DTC
To set B2585, the following conditions must be present:
| • | The key is in the RUN position. |
| • | The park brake is released. |
| • | The headlamp and panel dimmer switch in the AUTO mode. |
| • | The ambient light sensor is in the DARK state. |
| • | There is a short to ground in CKT 2409 or open CKT 1080. |
| • | If CKT 2409 is open regardless of the headlamp and panel dimmer switch position the DTC will set. |
| • | If CKT 1080 is open with the headlamp and panel dimmer switch in the AUTO mode the DTC will set. |
| • | The system voltage must be between 9.0-16.0 volts. |
| • | The above conditions must be met for 0.5 seconds. |
Action Taken When the DTC Sets
The parklamps will be inoperative in the AUTO mode.
Conditions for Clearing the MIL/DTC
| • | A current DTC will clear immediately when the condition for setting the fault is corrected with the key ON. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | Use a scan tool in order to clear the history and current DTCs. |
Diagnostic Aids
| Important: Use the appropriate probe from the J 35616 for any probing of the bussed electrical centers (BECs) in this table in order to avoid damage to the (BECs). |
| • | Always diagnose the first DTC listed on the scan tool. |
| • | The scan tool must display DTC B2585 as a current code before performing this set of diagnostics. |
| • | Perform a visual inspection for loose or poor connections at all related components. Refer to Intermittents and Poor Connections in Wiring Systems. |
Test Description
Step number(s) below refer to the same step number(s) in the Diagnostic Table.
-
This step determines if the PARK LPS fuse is open.
-
This step checks if CKT 74 (LT BLU) between the park lamp relay and the INT PARK fuse is open.
-
This step inspects if CKT 2409 (BRN) between the BCM and the INT PARK fuse is shorted to ground
-
This step inspects if CKT 1080 (WHT) between the BCM and the park lamp relay is open.
-
This step inspects the park lamp relay coil.
-
This step inspects if CKT 2409 (BRN) between the BCM and the INT PARK fuse is open.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the BCM Diagnostic System Check performed? | -- | ||
2 | Turn the headlamp and panel dimmer switch to the PARK position. Do the park lamps come ON? | -- | ||
3 |
Do the park lamps come ON? | -- | ||
4 | With a test lamp, test both sides of the PARK LPS fuse (in the UBEC) to ground. Does the test lamp light on both sides of the fuse? | -- | ||
5 |
Is the resistance between the specified range? | 0-5 ohms | ||
6 | If the test lamp lights on one side of the fuse locate the short to ground on CKT 240 or CKT 74. Did you find a short to ground? | -- | ||
7 | Repair the short to ground on CKT 240 or CKT 74. Is the repair complete | -- | -- | |
8 | Replace the UBEC. Is the repair complete? | -- | -- | |
9 | Inspect the INT PARK fuse (in the LBEC). Is the INT PARK fuse open? | -- | ||
10 |
Does the test lamp light? | -- | ||
11 |
Is the INT Park fuse open? | -- | Go to Intermittents and Poor Connections Diagnosis in Wiring Systems | |
12 |
| 0-5ohms | ||
13 |
Is the DTC still in current status? | -- | ||
14 |
Does the J 39200 DMM display battery voltage? | -- | ||
15 | Locate and repair the open CKT 240 (ORN) between the park relay and the PARK LPS fuse. Is the repair complete? | -- | -- | |
16 | Locate and repair the short to ground in CKT 2409 (BRN) wire replace fuse. Is the repair complete? | -- | -- | |
17 | Locate and repair the in open CKT 1080 (WHT) between the park lamp relay and the BCM. Is the repair complete? | -- | -- | |
18 | Replace the park lamp relay. Is the repair complete? | -- | -- | |
19 | Locate and repair the open in CKT 74 (LT BLU) between the INT PARK fuse and the park lamp relay cavity 87. Is the repair complete? | -- | -- | |
20 | Locate and repair the open in CKT 2409 (BRN) between the INT PARK fuse (LBEC) and the BCM. Is the repair complete? | -- | -- | |
21 |
Is the repair complete? | -- | System OK | -- |
22 | Clear the DTCs. Refer to Clearing DTCs . Is the repair complete? | -- | System OK | -- |
