GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. A Remote Keyless Doorlock Receiver (RCDLR) module was added midyear. The first step in diagnosing RKE problems on this vehicle is to determine which system this vehicle has.

  2. Lack of communication may be due to a partial malfunction of the class 2 serial data circuit or due to a total malfunction of the class 2 serial data circuit. The specified procedure will determine the particular condition.

  3. The presence of DTCs which begin with "U" indicate some other module is not communicating. The specified procedure will compile all the available information before tests are performed.

  4. At this point you have determined all DTCs which could affect the keyless entry system. Refer to Symptoms - Keyless Entry for further keyless entry diagnosis. Any other codes displayed from the listed modules do not apply to the keyless entry system and should be diagnosed in the applicable section.

Step

Action

Yes

No

Schematic Reference: Keyless Entry Schematics

1

Important: To determine which Remote Keyless Entry (RKE) system this vehicle has, open the trunk and inspect under the package shelf for the mounting tabs to a Remote Control Door Lock Reciever (RCDLR) module. The RCDLR is between the package shelf and the package shelf trim pad. If there is not a RCDLR module, this vehicle has RKE functions internal to the Body Control Module (BCM).

Refer to Keyless Entry Component Views .

Is there a RCDLR module under the package shelf?

Go to Step 2

Go to Step 7

2

Install a scan tool

Does the scan tool power up?

Go to Step 3

Go to Scan Tool Does Not Power Up in Data Link Communications

3

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the RCDLR module and the Body Control Module (BCM) by selecting Remote Function Actuator on the scan tool.

Does the scan tool communicate with the module?

Go to Step  4

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

4

Select the display DTCs function on the scan tool for the RCDLR and the BCM.

Does the scan tool display any DTCs?

Go to Step 5

Go to Symptoms - Keyless Entry

5

Does the scan tool display any DTCs which begin with a "U"?

Go to Scan Tool Does Not Communicate with Class 2 Device in Data Link Communications

Go to Step 6

6

Does the scan tool display DTC B1000 or B1001?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Step 7

7

Does the scan tool display DTC B1327 or B1328?

Go to Diagnostic Trouble Code (DTC) List in Doors

Go to Symptoms - Keyless Entry