Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
DTC Descriptor
DTC B3137: All Door Lock Circuit LowDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
BCM B+ | 1 | 1 | -- | -- |
Driver Door Lock Switch Signal | B3272 | 1 | 1 | -- |
Passenger Door Lock Switch Signal | B3272 | 1 | 1 | -- |
Driver Door Lock Control | B3127, B3137 | B3128, B3138 | 1 | -- |
Passenger Door Lock Control | B3132, B3137 | B3133, B3138 | 1 | -- |
Rear Door Lock Control | B3132, B3137 | B3133, B3138 | 1 | -- |
Driver Door Lock Switch Ground | -- | 1 | 1 | -- |
Passenger Door Lock Switch Ground | -- | 1 | 1 | -- |
1. Door Locks Malfunction | ||||
Circuit/System Description
The body control module (BCM), upon receipt of a lock switch lock signal, will provide and ground to the door latch unlock control circuit while simultaneously providing voltage to the door latch lock control circuit causing the door latch to perform the lock function. When the BCM receives a lock switch unlock signal, the BCM will provide and ground to the door latch lock control circuit while simultaneously providing voltage to the door latch unlock control circuit causing the door latch to perform the unlock function.
Conditions for Running the DTC
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
The BCM detects a short to ground in a door lock control circuit while commanding the door latches.
Action Taken When the DTC Sets
The power door locks will malfunction.
Conditions for Clearing the DTC
| • | This DTC will change from current to history when the fault is no longer present. |
| • | A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Reference Information
Schematic Reference
Door Lock/Indicator Schematics
Connector End View Reference
Description and Operation
Power Door Locks Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, observe the function of the doors while commanding the Passenger Door Unlock and Door Lock with a scan tool. All doors should perform the LOCK and UNLOCK function.
Circuit/System Testing
- Ignition OFF, disconnect the C2 harness connector at the left I/P junction block.
- Verify that a test lamp does not illuminate between the control circuit terminal B1 and B+.
- Disconnect the C2 harness connector at the right I/P junction block.
- Verify that a test lamp does not illuminate between the control circuit terminal A7 and B+.
- Disconnect the C2 harness connector at the BCM.
- Verify that a test lamp does not illuminate between the control circuit terminal A7 and B+.
| ⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the appropriate door lock. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the appropriate door lock. |
| ⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the appropriate door lock.
- Install a 20A fused jumper wire between one of the control terminals and 12V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the latch should perform the LOCK/UNLOCK functions.
| ⇒ | If it does not perform as specified, replace the door lock. |
Repair Instructions
| • | Control Module References for BCM replacement, setup, and programming |
