Circuit Description
The body control module (BCM) controls the courtesy lamps theater dimming. The BCM grounds the lamps directly. The ground will slowly reduce in order to turn the lamps to the OFF position. If there is an open or a short to ground condition in the courtesy lamp control circuit, DTC B2457 will set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2457 Courtesy Lamps Control Circuit Low
Conditions for Setting the DTC
The BCM detects a short to ground or an open in the courtesy lamp control circuit for more than 0.15 seconds.
Action Taken When the DTC Sets
| • | Stores DTC B2457 in the BCM memory. |
| • | No driver warning message will be displayed for this DTC. |
Conditions for Clearing the DTC
| • | The short to ground is no longer detected by the BCM on the courtesy lamp control circuit. |
| • | An open circuit is no longer detected by the BCM on the courtesy lamp control circuit. |
| • | A history DTC clears after 50 consecutive ignition cycles if the condition for the fault is no longer present. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Interior Lights Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Test the courtesy lamp control circuit of the body control module (BCM) for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 5 | Go to Step 3 | |
3 | Inspect for poor connections at the harness connector of the 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 5 | Go to Step 4 |
4 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 5 | -- |
5 |
Does the DTC reset? | Go to Step 2 | System OK |
