Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC B3140: Driver Unlock Switch CircuitDTC B3145: Passenger Unlock Switch Circuit
DTC B3150: Driver Lock Switch Circuit
DTC B3155: Right Front Lock Switch Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Relay Switch B+ | 1, 2, 3 | 1, 2, 3 | -- | -- |
Door Unlock Relay Control | B3130 | B3130 | B3130 | -- |
Driver Door Relay Unlock Control | B3125 | B3125 | B3125 | -- |
Door Lock Relay Control | B3135 | B3135 | -- | -- |
Driver Door Lock Switch Lock Signal | B3150 | B3150 | B3150 | -- |
Driver Door Lock Switch Unlock Signal | B3140 | B3140 | B3140 | -- |
Passenger Door Lock Switch Lock Signal | B3155 | B3155 | B3155 | -- |
Passenger Door Lock Switch Unlock Signal | B3145 | B3145 | B3145 | -- |
Door Lock Switch Ground | -- | 1, 2, 3 | 1, 2, 3 | -- |
I/P Fuse Block Ground | -- | 1, 2, 3 | 1, 2, 3 | -- |
1. Door Locks Inoperative 2. Driver Door Unlock Inoperative 3. Door Unlock Inoperative | ||||
Circuit/System Description
The body control module (BCM) supplies and monitors a reference voltage to the door lock switch through the door lock switch lock/unlock signal circuit. The door lock switch also receives a constant ground source. If a door lock switch is placed in the lock position or unlock position, the reference voltage is taken directly to ground and the BCM detects 0.0 volts on the signal circuit.
Conditions for Running the DTC
The system voltage must be between 9-16 volts.
Conditions for Setting the DTC
B3140 or B3150
The BCM detects a short to ground in the driver door lock switch lock or unlock signal circuits.
B3145 or B3155
The BCM detects a short to ground in the passenger door lock switch lock or unlock signal circuits.
Action Taken When the DTC Sets
| • | The BCM stores the DTC to memory. |
| • | The power door locks will not operate. |
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
Vehicle Access Connector End Views
Description and Operation
Power Door Locks Description and Operation
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
- Ignition ON, verify the appropriate scan tool Lock Sw parameter is Inactive.
- Verify the appropriate scan tool Unlock Sw parameter is Inactive.
- If all circuits test normal, test or replace the appropriate door lock switch.
| ⇒ | If not the specified value, test the signal circuit terminal L for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If not the specified value, test the signal circuit terminal U for a short to ground. If the circuit tests normal, replace the BCM. |
Component Testing
- Ignition OFF, disconnect the harness connector at the applicable door lock switch.
- Test for infinite resistance between the signal terminals U and L and the ground terminal C with the switch in the at rest position.
- Test for less than 2 ohms of resistance between the signal terminal L and the ground terminal C with the switch in the lock position.
- Test for less than 2 ohms of resistance between the signal terminal U and the ground terminal C with the switch in the unlock position.
| ⇒ | If less than infinite resistance, replace the applicable door lock switch. |
| ⇒ | If greater than 2 ohms, replace the applicable door lock switch. |
| ⇒ | If greater than 2 ohms, replace the applicable door lock switch |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
