GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Envoy - 4WD 🢒 Body and Accessories 🢒 Keyless Entry 🢒 Diagnostic System Check - Remote Keyless Entry

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. 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.

    2.

  2. 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.

    3.

  3. At this point you have determined all DTCs applicable to the Remote Keyless Entry System. Refer to Keyless Entry System Inoperative for further Remote Keyless Entry diagnosis. Any other body control module DTCs displayed do not apply to Remote Keyless Entry and should be diagnosed in their applicable section.

Step

Action

Yes

No

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

Go to Scan Tool Inoperative in Data Link Communications

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the Body Control Module.

Does the scan tool communicate with the Body Control Module?

Go to Step 3

Go to Diagnostic System Check - Body Control System in Body Control System

3

Select the Body Control Module display DTCs function on the scan tool.

Does the scan tool display any DTCs?

Go to Step 4

Go to Keyless Entry System Inoperative

4

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

Go to Diagnostic System Check - Data Link Communications in Data Link Communications

Go to Step 5

5

Does the scan tool display DTC B3102?

Go to DTC B3102 Keyless Entry (RFA) Data Link Circuit Lo in Body Control System

Go to Keyless Entry System Inoperative