Perform the Diagnostic System Check - Door Systems prior to using this diagnostic procedure.
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 |
The body control module (BCM), upon receipt of a lock switch lock signal, will provide a 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.
The system voltage must be between 9-16 volts.
• | Monte Carlo: The BCM detects a short to ground on the front passenger door unlock control circuit while commanding the door latches |
• | Impala: The BCM detects a short to ground on the front passenger, left rear or right rear door unlock control circuit while commanding the door latches |
The power door locks will malfunction.
• | 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. |
Door Lock/Indicator Schematics
Power Door Systems Connector End Views
Power Door Locks Description and Operation
Ignition ON, observe the function of the passenger door or left rear door and right rear door while commanding the Passenger Door Unlock and Door Lock with a scan tool. The doors should perform the LOCK and UNLOCK function.
⇒ | If the DTC is current on the Monte Carlo, refer to Monte Carlo Door Lock Malfunction |
⇒ | If the DTC is current on the Impala, refer to Impala Door Lock Malfunction |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, test or replace the left rear 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. |
⇒ | If it does not perform as specified, replace the door lock. |
• | Body Control Module (BCM) Programming/RPO Configuration for BCM replacement, setup, and programming |