GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2009 🢒 Regal 🢒 DTC 🢒 DTC B3797

Diagnostic Instructions
    • Perform the prior to Diagnostic System Check - Vehicle 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 Descriptor

DTC 3797 02: All Door Dead Lock Circuit Short to Ground

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Door Lock Switch Signal

B3150 00

B3150 000

B3150 00

--

Door Unlock Switch Signal

B3140 00, B3145 00

B3140 00, B3145 00

B3140 00, B3145 00

--

Driver Door Unlock Control

B3125 02

1, 2

1, 2

--

Doors Lock Control

B3135 02

1, 2, 3

1, 2, 3

--

Passenger Doors Unlock Control

B3130 02

1, 3

1, 3

--

Doors Dead Lock Control

B3797 02

1, 2, 3

1, 2, 3

--

Door Lock Switch Ground

--

1, 2, 3

1, 2, 3

--

1. Door Lock Malfunction

2. Driver Door Unlock Malfunction

3. Door Unlock Malfunction

Circuit/System Description

The body control module (BCM) controls the driver door lock relay.

Conditions for Running the DTC

The system voltage must be between 9-16 V.

Conditions for Setting the DTC

The BCM detects a short to ground in the doors dead lock circuit.

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

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

Ignition ON, command the Door Deadlock Lock/Unlock to Lock and Unlock with a scan tool. Listen or feel for the operation of the door relay clicking and the deadlock actuators locking and unlocking.

Circuit/System Testing
  1. Ignition OFF, disconnect the KR97D Driver Door Lock Relay
  2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 85 and ground.
    3. ⇒If the test lamp illuminates, test the control circuit for a short to voltage.
  3. Verify that a test lamp illuminates between the ground circuit terminal 86 and B+.
    4. ⇒If the test lamp does not illuminate, test the ground circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the KR97D Driver Door Lock Relay.
  4. Press the door unlock button on the door lock switch and verify that a test lamp illuminates between the door unlock control circuit terminal 30 and ground.
    5. ⇒If the test lamp does not illuminate, test the door unlock control circuit for an open/high resistance.
  5. Connect a 15 A fused jumper wire between the door unlock control circuit terminal 30 and the control circuit terminal 87A. Verify the door dead lock actuators are activated when the door lock switch is pressed.
    6. ⇒If the door dead lock actuators do not activate, test the control circuit for an open/high resistance.
  6. Connect a DMM, set on the diode setting, between the control circuit terminal 86 and ground.
  7. Command the Door Deadbolt Lock/Unlock to Unlock with a scan tool. The DMM reading should be greater than 2.5 V or display O.L.
    8. ⇒If less than the specified value, test the control circuit for a short to voltage or short to ground. If the circuits test normal, replace the K9 Body Control Module (BCM).
  8. Command the Door Deadbolt Lock/Unlock to Lock with a scan tool. The DMM reading should be less than 1 V.
    9. ⇒If greater than the specified range, test the control circuit for an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM).
  9. If all circuits test normal, test or replace the KR97D Driver Door Lock Relay.

Component Testing

Relay Test

  1. Ignition OFF, disconnect the KR97D Driver Door Lock Relay.
  2. Test for 60-180 Ω between terminals 85 and 86.
    3. ⇒If the resistance is not within the specified range, replace the KR97D Driver Door Lock Relay.
  3. Test for infinite resistance between the following terminals:
    4. • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    ⇒If not the specified value, replace the KR97D Driver Door Lock Relay.
  4. Install a 15 A fused jumper wire between relay terminal  85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87.
    5. ⇒If greater than the specified range, replace the KR97D Driver Door Lock Relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Relay Replacement
    •  Control Module References for BCM replacement, setup and programming