GM Service Manual Online
For 1990-2009 cars only

Circuit 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 a better description of window indexing, refer to Power Windows Description and Operation .

The RCDLR monitors the door latch enable control circuit voltage. If the voltage level is greater than 8 volts for longer than 2 minutes, a DTC is set.

    • DTC B2517 Left Front/Driver Door Latch Circuit
    • DTC B2518 Right Front/Passenger Door Latch Circuit

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

Stores DTC B2517 or B2518 in RCDLR memory.

Conditions for Clearing the DTC

    • The RCDLR no longer detects a voltage level greater than 8 volts in the door latch enable control circuit, and:
    • The DTC is cleared using a scan tool.

Diagnostic Aids

    • If the DTC does not reset after the code is cleared, it may be that the door latch enable control circuit is short 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.
    • If the DTC does not reset after the code is cleared, then the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Tests the door latch enable control circuit for a short to voltage.

  2. Tests the door latch control circuit for a short to voltage.

  3. Tests the body control module for a inoperative relay.

Step

Action

Yes

No

Schematic Reference: Door Lock/Indicator Schematics and Door Control Module Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Vehicle Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 3

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

3

  1. Turn OFF the ignition.
  2. Disconnect the appropriate power door latch.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.
  5. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 6

Go to Step 4

4

Probe the door latch control circuit of the appropriate power door latch harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 7

5

  1. Turn OFF the ignition.
  2. Disconnect the body control module (BCM) C3 harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the door latch control circuit of the appropriate power door latch harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 10

Go to Step 8

6

Test the appropriate door latch enable control circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 9

7

Inspect for poor connections at the harness connector of the appropriate door latch motor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 11

8

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 12

9

Inspect for poor connections at the harness connector of the remote control door lock receiver (RCDLR). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

Go to Step 13

10

Repair the short to voltage in the appropriate door latch enable control circuit. Refer to Wiring Repairs and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 14

--

11

Replace the appropriate door latch motor. Refer to Door Lock Replacement .

Did you complete the replacement?

Go to Step 14

--

12

  1. Perform the set-up procedure for the BCM. Refer to Body Control Module (BCM) Programming/RPO Configuration in Computer/Integrating Systems.
  2. Replace the BCM. Refer to Body Control Module Replacement in Computer/Integrating Systems.

Did you complete the replacement?

Go to Step 14

--

13

Replace the RCDLR. Refer to Remote Control Door Lock Receiver Replacement in Keyless Entry.

Did you complete the replacement?

Go to Step 14

--

14

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK