GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 Savana 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B3140, B3145, B3150, or B3155

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 00: Driver Unlock Switch Circuit

DTC B3145 00: Passenger Unlock Switch Circuit

DTC B3150 00: Driver Lock Switch Circuit

DTC B3155 00: Passenger Lock Switch Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Door Lock/Unlock Relay B+

1

1

--

--

Driver Door Lock Switch Lock Signal

B3150 00

B3150 00

B3150 00

--

Driver Door Lock Switch Unlock Signal

B3140 00

B3140 00

B3140 00

--

Passenger/Cargo Door Lock Switch Lock Signal

B3155 00

B3155 00

B3155 00

--

Passenger/Cargo Door Lock Switch Unlock Signal

B3145 00

B3145 00

B3145 00

--

Passenger/Cargo Unlock Relay Control

B3130 00

B3130 00

B3130 00

--

Driver Unlock Relay Control

B3125 00

B3125 00

B3125 00

--

Door Lock Relay Control

B3135 00

B3135 00

B3135 00

--

Cargo Unlock Relay Control

2

2

2

--

Door Lock Switch Ground

--

3

3

--

Door Lock/Unlock Relay Ground

--

1

1

--

1. All Latches Malfunction

2. Cargo Door Latch Malfunction

3. Door Lock Switch Malfunction

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 the drop in voltage on the signal circuit.

Conditions for Running the DTC

The system voltage is 9-16 volts.

Conditions for Setting the DTC

B3140 00 or B3150 00

The BCM detects a short to ground in the driver door lock switch lock or unlock signal circuits.

B3145 00 or B3155 00

The BCM detects a short to ground in the passenger door lock switch or cargo door lock switch lock or unlock signal circuits.

Action Taken When the DTC Sets

The power door lock switch will malfunction

Conditions for Clearing the DTC
    • The DTC will be current for as long as the fault is present.
    • When the fault is no longer present, the DTC will be a history DTC.
    • A history DTC will clear after 50 ignition cycles.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Door Locks Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification
  1. Ignition ON, observe the scan tool Driver Door Lock Sw and Driver Door Unlock Sw parameters while using the driver door lock switch. The parameter should change from Inactive to Active.
    2. ⇒If the parameter does not change, refer to Driver Door Lock Switch Malfunction.
  2. Observe the scan tool Psgr Door Lock Sw and Psgr Door Unlock Sw parameters while using the passenger and cargo door lock switches. The parameter should change from Inactive to Active.
    3. ⇒If the parameter does not change, refer to Passenger/Cargo Door Lock Switch Malfunction.

Circuit/System Testing

Driver Door Lock Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the driver door lock switch.
  2. Ignition ON, verify the scan tool Driver Door Lock Sw parameter is Inactive.
    3. ⇒If not the specified value, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the BCM.
  3. Verify the scan tool Driver Door Unlock Sw parameter is Inactive.
    4. ⇒If not the specified value, test the signal circuit terminal G for a short to ground. If the circuit tests normal, replace the BCM.
  4. Install a 3 amp fused jumper wire between the signal circuit terminal F and ground. Verify the scan tool Driver Door Unlock Sw parameter is Active.
    5. ⇒If not the specified parameter, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  5. Install a 3 amp fused jumper wire between the signal circuit terminal G and ground. Verify the scan tool Driver Door Lock Sw parameter is Active
    6. ⇒If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  6. If all circuits test normal, test or replace the driver door lock switch.

Passenger/Cargo Door Lock Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the passenger and cargo door lock switches.
  2. Verify the scan tool Psgr Door Lock Sw parameter is Inactive.
    3. ⇒If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
    • Passenger door lock switch signal circuit terminal F
    • Rear cargo door lock switch signal circuit terminal A
  3. Verify the scan tool Psgr Door Unlock Sw parameter is Inactive.
    4. ⇒If not the specified value, test the signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the BCM.
    • Passenger door lock switch signal circuit terminal G
    • Rear cargo door lock switch signal circuit terminal D
  4. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground:
    5. • Passenger door lock switch signal circuit terminal F.
    • Rear cargo door lock switch signal circuit terminal A.
  5. Verify the scan tool Psgr Door Lock Sw parameter is Active.
    6. ⇒If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  6. Install a 3A fused jumper wire between the signal circuit terminal listed below and ground:
    7. • Passenger door lock switch signal circuit terminal G.
    • Rear cargo door lock switch signal circuit terminal D.
  7. Verify the scan tool Psgr Door Unlock Sw parameter is Active.
    8. ⇒If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
  8. Ignition OFF, connect the harness connector at the passenger door lock switch.
  9. Ignition ON, observe the Psgr Door Lock Sw and Psgr Door Unlock Sw parameters while using the passenger door lock switch. The parameters should change from Inactive to Active.
    10. ⇒If the parameters do not change, test or replace the passenger door lock switch.
  10. If all circuits test normal, test or replace the cargo door lock switch.

Component Testing

Door Lock Switch Test

  1. Ignition OFF, disconnect the harness connector at the appropriate door lock switch.
  2. Test for infinite resistance between the signal terminals and the ground terminal listed below with the switch in the inactive position:
    3. • Driver door lock switch terminal F and A
    • Driver door lock switch terminal G and A
    • Passenger door lock switch terminal F and A
    • Passenger door lock switch terminal G and A
    • Rear cargo door lock switch terminal A and E
    • Rear cargo door lock switch terminal D and E
    ⇒If less than the specified value, replace the door lock switch.
  3. Test for less than 2 ohms between the signal terminal and the ground terminal listed below with the switch in the lock position:
    4. • Driver door lock switch terminal F and A
    • Passenger door lock switch terminal F and A
    • Rear cargo door lock switch terminal A and E
    ⇒If greater than the specified value, replace the door lock switch.
  4. Test for less than 2 ohms between the signal terminal and the ground terminal listed below with the switch in the unlock position:
    5. • Driver door lock switch terminal G and A
    • Passenger door lock switch terminal G and A
    • Rear cargo door lock switch terminal D and E
    ⇒If greater than the specified value, replace the door lock switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Door Lock Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming