GM Service Manual Online
For 1990-2009 cars only

Object Number: 610424  Size: MF

Circuit Description

The remote control door lock receiver (RCDLR) communicates with the body control module (BCM) through the keyless entry serial data circuit.

When any button on the keyless entry transmitter is pressed, the transmitter sends a signal to the RCDLR.

The RCDLR sends either a lock or unlock request to the BCM, depending on which button is pressed on the transmitter.

The BCM receives the message and performs the appropriate function.

Conditions for Setting the DTC

The BCM detects an open, a short to voltage, or a short to ground in the keyless entry serial data circuit.

Action Taken When the DTC Sets

    • The BCM sets the diagnostic trouble code (DTC) 8.
    • The keyless entry system remains inoperative. The power sliding door may still be operational because the RCDLR operates the power sliding door directly without using the BCM.

Conditions for Clearing the MIL/DTC

    • An open, a short to voltage, or a short to ground in the keyless entry serial data circuit is no longer present between the BCM and the RCDLR.
    • After the repairs are completed, refer to Diagnostic Trouble Code (DTC) Clearing in order to clear the DTC.

Diagnostic Aids

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. Always perform the keyless entry diagnostic system check before attempting to diagnose DTC 8.

  2. This step tests for B+ on the keyless entry serial data circuit.

  3. This step tests the keyless entry serial data circuit for a short to voltage.

  4. This step tests the keyless entry serial data circuit for a high resistance or an open.

  5. This step tests the keyless entry serial data circuit for a short to ground.

Step

Action

Value(s)

Yes

No

1

Did you perform the keyless entry diagnostic system check?

--

Go to Step 2

Go to Diagnostic System Check - Remote Keyless Entry

2

  1. Turn OFF the ignition.
  2. Disconnect the remote control door lock receiver (RCDLR) connector.
  3. Turn ON the ignition, with engine OFF.
  4. Measure the voltage from the keyless entry serial data circuit of the RCDLR connector to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Connect a test lamp between the keyless entry serial data circuit of the RCDLR connector and a good ground.
  3. Turn ON the ignition.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 6

4

Test the keyless entry serial data circuit for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 5

5

Test the keyless entry serial data circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the harness connector of the 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 11

Go to Step 10

7

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 11

Go to Step 9

8

Repair the short to voltage in the keyless entry serial data circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 11

--

9

Important: Perform the BCM programming procedure when replacing the BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control Systems.

Did you complete the repair?

--

Go to Step 11

--

10

Important: Perform the RCDLR programming procedure when replacing the RCDLR. Refer to Transmitter Programming .

Replace the RCDLR. Refer to Receiver Replacement .

Did you complete the repair?

--

Go to Step 11

--

11

  1. Clear the BCM DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing in Body Control Systems.
  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

--