GM Service Manual Online
For 1990-2009 cars only

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 B2517: Left Front/Driver Door Latch Circuit

DTC B2518: Right Front/Passenger Door Latch Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Door Latch Control

1

1

B2517, 1

--

Driver Door Latch Enable Control

1

1

B2517, 1

--

Front Passenger Door Latch Control

1

1

B2518, 1

--

Front Passenger Door Latch Enable Control

1

1

B2518, 1

--

Driver Door Lock Switch Lock Signal

B3152, 2

2

2

--

Driver Door Lock Switch Unlock Signal

B3142, 2

2

2

--

Left Front Exterior Door Handle Switch Signal

B3849, 2

1

1

--

Left Front Interior Door Handle Switch Signal

B3848, 2

1

1

--

Passenger Door Lock Switch Lock Signal

B3155, 2

2

2

--

Passenger Door Lock Switch Unlock Signal

B3145, 2

2

2

--

Right Front Exterior Door Handle Switch Signal

B1474, 1

1

1

--

Right Front Interior Door Handle Switch Signal

B2981, 1

1

1

--

Door Handle Switch - Driver Exterior Ground

--

1

1

--

Door Handle Switch - Driver Interior Ground

--

1

1

--

Door Handle Switch - Passenger Exterior Ground

--

1

1

--

Door Handle Switch - Passenger Interior Ground

--

1

1

--

Door Lock Switch - Driver Ground

--

2

2

--

Door Lock Switch - Passenger Ground

--

2

2

--

1. Power Door Latch System Malfunction

2. Power Door Locks Inoperative

Circuit/System Description

The remote control door lock receiver (RCDLR), driver door module (DDM), passenger door module (PDM) and body control module (BCM) control the output functions of the power door latches. These output functions allow the RCDLR and BCM to command the power door latch motors to Unlatch.

When the RCDLR receives an input from one of the door handle switches, it checks the Lock/Unlock status of the door. If the status of the door is Unlock, the RCDLR applies the ground for the appropriate power door latch.

At the same time that the RCDLR is receiving its input, the DDM or PDM is also receiving the same input. When the DDM or PDM receives its input from the door handle switch, it checks the window indexing status of the door. If the window is below the index point, it sends a serial data message to the BCM to apply voltage for the appropriate power door latch. If the window is above the index point, it will first index the window, then send a serial data message to the BCM to apply voltage for the power door latch. For more detailed information concerning power door latch operation refer to Power Door Latch Description and Operation .

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • The RCDLR detects voltage greater than 8 volts in the door latch enable control circuit.
    • Condition must be present for longer than 2 minutes.

Actions Taken When the DTC Sets

Stores DTC B2517 or B2518 in RCDLR memory.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

    • If the DTC does not reset after the code is cleared, it may be that the door latch enable control circuit is shorted to voltage. If the voltage circuit that the door lock enable control circuit is shorted to is fused, then the fuse for the voltage circuit would open when a door handle switch is activated and the RCDLR pulls the door lock enable control circuit low. Check related systems for an open fuse.
    • An intermittent short to voltage in a door latch control, or a door latch enable control circuit may cause an intermittent malfunction.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics

Connector End View Reference

Vehicle Access Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Data Definitions
    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Testing

  1. Ignition OFF, disconnect the appropriate door latch harness connector.
  2. Ignition OFF, test for less than 1 ohm of resistance between the appropriate door latch enable control circuit and ground.
  3. If greater than the specified range, test the door latch enable control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the RCDLR.
  4. Ignition OFF, test for less than 1 ohm of resistance between the appropriate door latch control circuit and ground.
  5. If greater than the specified range, test the door latch control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the BCM.
  6. If all circuits test normal, test or replace the appropriate door latch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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