GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the entire Headlight System Check performed?

--

Go to Step 2

Go to Headlight System Check

2

Disconnect the headlamp switch connector.

Do the high beam headlamps turn off?

--

Go to Step 9

Go to Step 3

3

Disconnect the dash integration module (DIM) connector C2.

Do the high beam headlamps turn off?

--

Go to Step 10

Go to Step 4

4

Disconnect the dash integration module (DIM) connector C1.

Do the high beam headlamps turn off?

--

Go to Step 11

Go to Step 5

5

Disconnect the headlamp dimmer switch connector C202.

Do the high beam headlamps turn off?

--

Go to Step 12

Go to Step 6

6

Disconnect the underhood junction block connector C2.

Do the high beam headlamps turn off?

--

Go to Step 13

Go to Step 7

7

Remove the HDLP HI BM relay from the underhood junction block .

Do the high beam headlamps turn off?

--

Go to Step 14

Go to Step 8

8

Replace the underhood junction block . Refer to Underhood Fuse Block Replacement in Engine Electrical.

Is the underhood junction block replacement complete?

--

Go to Headlight System Check

--

9

Replace the headlamp switch. Refer to Headlamp Switch Replacement in Instrument Panel, Gauges and Console.

Is the headlamp switch replacement complete?

--

Go to Headlight System Check

--

10

Repair the short to ground in CKT 103 (WHT). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Headlight System Check

--

11

Replace the dash integration module (DIM). Refer to Body Control Module Replacement in Body Control System.

Is the DIM replacement complete?

--

Go to Headlight System Check

--

12

Replace the headlamp dimmer switch. Refer to Turn Signal and Multifunction Switch Assembly - Off Vehicle in Steering Wheel and Column-Tilt.

Is the headlamp dimmer switch replacement complete?

--

Go to Headlight System Check

--

13

Repair the short to ground in CKT 1969 (BLK/WHT). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Headlight System Check

--

14

Replace the HDLP HI BM relay in the underhood junction block. Refer to Wiring Repairs in Wiring Systems

Do the high beam headlamps turn off?

--

Go to Headlight System Check

Go to Step 8