GM Service Manual Online
For 1990-2009 cars only

Component Illumination Lamps Inoperative A/T Indicator Lamp

Step

Action

Value(s)

Yes

No

Important: This test assumes that all of the other lamps on the dimming circuit operate properly. This test will diagnose the automatic transmission indicator lamp and the automatic transmission preference switch illumination (if equipped). If any other symptoms exist, refer to Instrument Panel Lamps Inoperative in order to test the primary dimming circuit.

1

Did you perform the Interior Lights Dimming System Check?

--

Go to Step 2

Go to Interior Lights Dimming System Check

2

Does the driver information display module illumination operate properly?

--

Go to Step 4

Go to Step 3

3

Locate and repair an open in CKT 1220 (GRY) between C203 and S205.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

4

  1. Move the headlamp switch to the PARK position.
  2. Turn the dimmer switch to full intensity.
  3. Backprobe the automatic transmission indicator lamp connector terminal A to ground.

Is the voltage within the specified range?

10-11 V

Go to Step 8

Go to Step 5

5

Backprobe the automatic transmission preference connector terminal B to ground.

Is the voltage within the specified range?

10-11 V

Go to Step 7

Go to Step 6

6

Locate and repair an open in CKT 1220 (GRY) between S336 and C203.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

7

Locate and repair an open in CKT 1220 (GRY) between S336 and the automatic transmission indicator lamp.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

8

Backprobe the automatic transmission indicator lamp connector terminal A to terminal B.

Is the voltage within the specified range?

10-11 V

Go to Interior Lights Dimming System Check

Go to Step 9

9

Backprobe the automatic transmission preference switch connector terminal B to terminal A.

Is the voltage within the specified range?

10-11 V

Go to Step 11

Go to Step 10

10

Locate and repair an open in CKT 1850.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

11

Locate and repair an open in CKT 1850 between S335 and automatic transmission indicator lamp terminal B.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

Component Illumination Lamps Inoperative Overhead Console

Step

Action

Value(s)

Yes

No

Important: This test assumes that all of the other lamps on the dimming circuit operate properly. If any other symptoms exist, refer to Instrument Panel Lamps Inoperative in order to test the primary dimming circuit.

1

Did you perform the Interior Lights Dimming System Check?

--

Go to Step 2

Go to Interior Lights Dimming System Check

2

  1. Move the headlamp switch to the PARK position.
  2. Turn the dimmer switch to full intensity.

Does the automatic transmission indicator lamp illuminate?

--

Go to Step 4

Go to Step 3

3

Locate and repair an open in CKT 1220 (GRY) between C203 and S205.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

4

  1. Move the headlamp switch to the PARK position.
  2. Turn the dimmer switch to full intensity.
  3. Backprobe the driver information display module connector C1 terminal 9 (w/o trip computer) or terminal 11 (w/ trip computer) to ground.

Is the voltage within the specified range?

10-11 V

Go to Step 6

Go to Step 5

5

Locate and repair an open in CKT 1220 (GRY) between C203 and the driver information display module.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--

6

Replace the driver information display module.

Is the repair complete?

--

Go to Interior Lights Dimming System Check

--