GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 Envoy - 2WD 🢒 Accessories 🢒 Entertainment 🢒 Diagnostic System Check - Body Rear End

Test Description

The numbers below refer to the step numbers 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.

Step

Action

Yes

No

1

Install a scan tool.

Does the scan tool power up?

Go to Step 2

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

2

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to establish communication with the End Gate Module.
  3. Attempt to establish communication with the Lift Gate Module.

Does the scan tool communicate with the End Gate Module and Lift Gate Module?

Go to Step 3

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

3
  1. Select the display DTCs for the End Gate Module.
  2. Select the display DTCs for the Lift Gate Module.

Does the scan tool display any DTCs?

Go to Step 4

Go to Symptoms - Body Rear End

4

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 5

5

Does the scan tool display DTC B1000, B1004, B1007, or B1009?

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

Go to Step 6

6

Does the scan tool display DTC B1539, B1540, B3745, B3964, B3965, B3966 or B3967?

Go to Diagnostic Trouble Code (DTC) List

Go to Symptoms - Body Rear End