Circuit Description
The body control module (BCM) provides an output to the driver switch assembly through the door unlock control circuit for controlling automatic door unlock, anti-lockout, and keyless entry unlock functions.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B3142 Unlock Switch Circuit Low |
| • | DTC B3143 Unlock Switch Circuit High |
Conditions for Setting the DTC
| • | The BCM detects a short to ground on the door unlock control circuit for greater than 60 seconds. |
| • | The BCM detects a short to battery on the door unlock control circuit for greater than 1 second. |
Action Taken When the DTC Sets
| • | The BCM stores DTC B3142 or B3143 in memory. |
| • | The BCM will disable the output and all operations of the output until the fault no longer exists. |
Conditions for Clearing the DTC
| • | The BCM no longer detects the short to ground on the door unlock control circuit for greater than 60 seconds. |
| • | The BCM no longer detects the short to battery on the door unlock control circuit for greater than 1 second. |
| • | 100 consecutive ignition cycles have been recorded without the DTC being detected. |
Diagnostic Aids
If DTC B3142 or B3143 are history DTCs, the fault 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.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Door Lock/Indicator Schematics Connector End View Reference: Vehicle Access Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
Does the DTC reset? | Go to Step 3 | Go to Step 4 | |
3 | Test the door unlock control circuit for a short to ground or voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 5 |
4 | Inspect for poor connections at the harness connector of the driver switch assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 6 |
5 | 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 8 | Go to Step 7 |
6 | Replace the driver switch assembly. Refer to Door Lock Switch Replacement - Driver Door . Did you complete the replacement? | Go to Step 8 | -- |
7 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | -- |
8 |
Does the DTC reset? | Go to Step 2 | System OK |
