Circuit Description
When the body control module (BCM) receives a class 2 signal from the powertrain control module (PCM) or engine control module (ECM) indicating the gear selector is in the REVERSE position, the BCM applies positive voltage to the backup lamps supply voltage circuit. The backup lamps are grounded at G301 for the left backup lamp and G302 for the right backup lamp.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2545 Backup Lamps Circuit
Conditions for Running the DTC
| • | The battery voltage must be between 9-16 volts. |
| • | The gear selector must be placed in and out of the REVERSE position. |
Conditions for Setting the DTC
| • | When the CHMSL BACK/UP Fuse is open. |
| • | When the backup lamps supply voltage circuit is shorted to ground or shorted to voltages. |
| • | When the backup lamps supply voltage circuit is open before the first splice. |
| • | When circuit 1240 is open or shorted to voltage. |
Action Taken When the DTC Sets
The backup lamps will not operate properly.
Conditions for Clearing the DTC
| • | This DTC will clear on current status after the condition for setting the fault is corrected. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | History and current DTCs can be cleared using a scan tool. |
Diagnostic Aids
Perform a visual inspection for loose or poor connections at all related components. Refer to Testing for Intermittent Conditions and Poor Connections .
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 | |||||||
2 |
Do the backup lamps turn ON and OFF as expected? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||
3 | Test the backup lamps voltage supply circuit for the following:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 7 | Go to Step 4 | ||||||
4 | Test the battery positive voltage circuit between the body control module (BCM) and the CHMSL BACK/UP Fuse for an open or short to ground. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 | ||||||
5 | Inspect for poor connection at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 7 | Go to Step 6 | ||||||
6 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 7 | -- | ||||||
7 |
Does the DTC reset? | Go to Step 2 | System OK | ||||||
