GM Service Manual Online
For 1990-2009 cars only

Stop Lamps Inoperative - Center High Mounted Domestic

Step

Action

Value(s)

Yes

No

1

Was the Exterior Lights System Check performed?

--

Go to Step 2

Go to Exterior Lights System Check

2

Is one lamp inoperative?

--

Go to Step 6

Go to Step 3

3

  1. Remove the left bulb from the center high mounted stoplamp assembly.
  2. Connect a J 39200 DMM between the left center high mounted stoplamp bulb, cavity A for CKT 17 (WHT), and ground.

Is continuity present?

--

Go to Step 4

Go to Step 5

4

Repair the open in CKT 150 (BLK) between splice S421 and ground G400.

Are both center high mounted stoplamp bulbs operative?

--

Go to Exterior Lights System Check

Go to Step 5

5

Repair the open in CKT 17 (WHT) between splice S410 and splice S422.

Are both center high mounted stoplamp bulbs operative?

--

Go to Exterior Lights System Check

Go to Step 6

6

Is the left center high mounted stoplamp bulb operative?

--

Go to Step 13

Go to Step 7

7

  1. Remove the left bulb from the center high mounted stoplamp assembly.
  2. Connect a J 39200 DMM between the left bulb center high mounted stoplamp connector, cavity B for CKT 150 (BLK), and ground.

Is continuity present?

--

Go to Step 9

Go to Step 8

8

Repair the open in CKT 150 (BLK) between the left bulb center high mounted stoplamp connector and splice 421.

Is the left center high mounted stoplamp bulb operative?

--

Go to Step 12

Go to Step 9

9

  1. Connect an unpowered test lamp between the left bulb center high mounted stoplamp connector, cavity A for CKT 17 (WHT), and ground.
  2. Depress the brake pedal.

Does the test lamp light?

--

Go to Step 10

Go to Step 11

10

Replace the left bulb in the center high mounted stoplamp.

Is the left center high mounted stoplamp bulb operative?

--

Go to Step 12

Go to Step 11

11

Repair the open in CTK 17 (WHT) between splice S422 and the connector for the left bulb in the center high mounted stoplamp.

Is the right center high mounted stoplamp bulb operative?

--

Go to Exterior Lights System Check

Go to Step 13

12

Is the right center high mounted stoplamp bulb operative?

--

Go to Exterior Lights System Check

Go to Step 13

13

  1. Remove the right bulb from the center high mounted stoplamp assembly.
  2. Connect a J 39200 DMM between the right bulb center high mounted stoplamp connector, cavity B for CKT 150 (BLK), and ground.

Is continuity present?

--

Go to Step 15

Go to Step 14

14

Repair the open in CKT 150 (BLK) between the right bulb center high mounted stoplamp connector and splice 421.

Is the right center high mounted stoplamp bulb operative?

--

Go to Exterior Lights System Check

Go to Step 15

15

  1. Connect an unpowered test lamp between the right bulb center high mounted stoplamp connector, cavity A for CKT 17 (WHT), and ground.
  2. Depress the brake pedal.

Does the test lamp light?

--

Go to Step 16

Go to Step 17

16

Replace the right bulb in the center high mounted stoplamp.

Is the right center high mounted stoplamp bulb operative?

--

Go to Exterior Lights System Check

Go to Step 17

17

Repair the open in CTK 17 (WHT) between splice S422 and the connector for the right bulb in the center high mounted stoplamp.

Is the right center high mounted stoplamp bulb operative?

--

Go to Exterior Lights System Check

--

Stop Lamps Inoperative - Center High Mounted Export

Step

Action

Value(s)

Yes

No

1

Was the Exterior Lights System Check performed?

--

Go to Step 2

Go to Exterior Lights System Check

2

  1. Remove the center high mounted stop lamp assembly.
  2. Connect a J 39200 DMM between the CHMSL connector C419 cavity B and ground.

Is continuity present?

--

Go to Step 3

Go to Step 4

3

  1. Connect an unpowered test lamp between the center high mounted stop lamp connector C419 Cavity A and ground.
  2. Depress the brake pedal.

Does the test lamp light?

--

Go to Step 5

Go to Step 6

4

Repair the open in CKT 150 (BLK) between the center high mounted stop lamp connector C419 Cavity B and ground G400.

Is the repair complete?

--

Go to Exterior Lights System Check

--

5

Replace the center high mounted stop lamp assembly.

Is the repair complete?

--

Go to Exterior Lights System Check

--

6

Repair the open in CKT 17 (WHT) between splice S410 and the connector C419 Cavity A at the center high mounted stop lamp.

Is the repair complete?

--

Go to Exterior Lights System Check

--