GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

  1. Connect the test lamp from CKT 1962 (BLK/WHT) at the Exhaust Brake Solenoid Valve to the chassis ground.
  2. Turn the ignition switch to RUN.
  3. Turn the Exhaust Brake Switch ON.

Did the test lamp light?

--

Go to Step 2

Go to Step 3

2

Connect the test lamp from CKT 1962 (BLK/WHT) to the CKT 150 (BLK) wire at the Exhaust Brake Solenoid Valve.

Did the test lamp light?

--

Go to Step 13

Go to Step 12

3

Connect a test lamp from CKT 1962 (BLK/WHT) at the Exhaust Brake Accelerator Switch to the chassis ground.

Did the test lamp light?

--

Go to Step 14

Go to Step 4

4

Connect a test lamp from CKT 48 (GRY) at the Exhaust Brake Accelerator Switch to the chassis ground.

Did the test lamp light?

--

Go to Step 15

Go to Step 5

5

Is the vehicle equipped with Air ABS?

--

Go to Step 6

Go to Step 8

6

Connect a test lamp from CKT 48 (GRY) at the Exhaust Brake Disable Relay terminal C6 to the chassis ground.

Did the test lamp light?

--

Go to Step 16

Go to Step 7

7

Connect a test lamp from CKT 48 (GRY) terminal B7 at the Exhaust Brake Disable Relay to the chassis ground.

Did the test lamp light?

--

Go to Step 8

Go to Step 17

8

Connect a test lamp from CKT 48 (GRY) at the Exhaust Brake Clutch Switch or the Exhaust Brake Clutch Switch Jumper Plug to the chassis ground.

Did the test lamp light?

--

Go to Step 18

Go to Step 9

9

Connect a test lamp from CKT 1961 (WHT) at the Exhaust Brake Clutch Switch to the chassis ground.

Did the test lamp light?

--

Go to Step 19

Go to Step 10

10

Connect a test lamp from CKT 1961 (WHT) at the Exhaust Brake Switch to the chassis ground.

Did the test lamp light?

--

Go to Step 20

Go to Step 11

11

Connect a test lamp from CKT 341 (BRN) at the Exhaust Brake Switch to the chassis ground.

Did the test lamp light?

--

Go to Step 21

Go to Step 22

12

Repair an open in CKT 150 (BLK) between the Exhaust Brake Solenoid Valve and the chassis ground.

Is the repair complete?

--

System OK

--

13

Replace the Exhaust Brake Solenoid Valve.

Is the repair complete?

--

System OK

--

14

Repair an open in CKT 1962 (BLK/WHT) between the Exhaust Brake Accelerator Switch and the Exhaust Brake Solenoid Valve.

Is the repair complete?

--

System OK

--

15

Replace the Exhaust Brake Accelerator Switch.

Is the repair complete?

--

System OK

--

16

Repair an open in CKT 48 (GRY) between the Exhaust Brake Disable Relay and the Exhaust Brake Accelerator Switch.

Is the repair complete?

--

System OK

--

17

Replace the Exhaust Brake Disable Relay.

Is the repair complete?

--

System OK

--

18

Repair an open in CKT 48 (GRY) between the Exhaust Brake Clutch Switch and the Exhaust Brake Disable Relay or the Exhaust Brake Accelerator Switch.

Is the repair complete?

--

System OK

--

19

Replace the Exhaust Brake Clutch Switch.

Is the repair complete?

--

System OK

--

20

Repair an open in CKT 1961 (WHT) between the Exhaust Brake Switch and the Exhaust Brake Clutch Switch or the Exhaust Brake Clutch Switch Jumper Plug.

Is the repair complete?

--

System OK

--

21

Replace the Exhaust Brake Switch.

Is the repair complete?

--

System OK

--

22

Repair an open in CKT 341 (BRN) between the I/P Fuse Block and the Exhaust Brake Switch.

Is the repair complete?

--

System OK

--