Schematic Reference: Interior Lights Dimming Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

1. Turn ON the ignition, with the engine OFF.
2. Place the headlamp switch in the PARK position.
3. Cover the sunload sensor.
4. Turn the instrument panel (I/P) lamps dimmer switch from minimum to maximum intensity.

Do the interior backlighting lamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

Are all of the interior backlighting lamps always ON?

Go to Step 4

Go to Step 9

1. Install a scan tool.
2. With a scan tool, observe the Dimming Potentiometer parameter in the Dash Integration Module (DIM) Inputs data list.
3. Move the I/P lamps dimmer switch from minimum to maximum intensity.

Does the scan tool indicate that the Dimming Potentiometer parameter is changing when the I/P lamps dimmer switch is moved?

Go to Step 5

Go to Step 7

With a scan tool, observe the Park Lamp Switch status in the DIM Inputs data list.

Does the scan tool display ON?

Go to Step 6

Go to Step 8

With a scan tool, observe the Photocell Status parameter in the Climate Control Panel (CCP) Lighting Data list.

Does the scan tool display DARK?

Go to Step 11

Go to Twilight Sentinel Inoperative

Test the I/P lamps dimmer switch signal circuit for an short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 10

Test the park lamp relay control circuit for an open circuit or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 11

Inspect for poor connections at the harness connector of the appropriate controlling module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 12

Inspect for poor connections at the harness connector of the I/P lamps dimmer switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 13

Inspect for poor connections at the harness connector of the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 15

Go to Step 14

Replace the appropriate controlling module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

--

Replace the I/P lamps dimmer switch. Refer to Instrument Panel Lamp Dimmer Switch Replacement .

Did you complete the replacement?

Go to Step 15

--

Replace the DIM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 15

--

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2