Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Defogger Schematics Connector End View Reference: Stationary Windows Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Important: Verify that system voltage is within the normal operating range for the vehicle. Low operating voltage will effect the illumination of the rear window defogger indicator.
Does the rear window defogger indicator illuminate? | Go to Step 3 | Go to Step 10 |
3 | Connect a test lamp between the rear window defogger grid and a good ground. Does the test lamp illuminate? | Go to Step 4 | Go to Step 5 |
4 | Connect a test lamp between the left side of the rear window defogger grid and the right side of the rear window defogger grid. Does the test lamp illuminate? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 14 |
5 | Command the rear defog relay ON and OFF, by depressing the rear defogger switch on the HVAC control module. Do you hear a click when you command the Rear Defog relay ON and OFF? | Go to Step 8 | Go to Step 6 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 15 |
7 |
Does the test lamp illuminate? | Go to Step 13 | Go to Step 10 |
8 |
Does the test lamp illuminate? | Go to Step 9 | Go to Step 11 |
9 |
Does the test lamp illuminate? | Go to Step 13 | Go to Step 17 |
10 | Test the control circuit of the rear defog relay for an open or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 20 | Go to Step 12 |
11 | Test the battery positive voltage circuit of the rear defog relay switched input for an open or short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 20 | Go to Step 16 |
12 | Inspect for a poor connection at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 20 | Go to Step 18 |
13 | Inspect for poor connections at the rear defog relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 20 | Go to Step 19 |
14 | Locate and repair an open or high resistance in the ground circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | -- |
15 | Locate and repair an open or high resistance in the ignition voltage circuit of the rear defog relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | -- |
16 | Locate and repair a short to ground in the supply voltage circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | -- |
17 | Locate and repair an open or high resistance in the supply voltage circuit of the rear window defogger grid. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 20 | -- |
18 | Replace the HVAC control module. Refer to Control Module References in Computer/Integrating Systems. Did you complete the replacement? | Go to Step 20 | -- |
19 | Replace the rear defog relay. Refer to Relay Replacement in Wiring Systems. Did you complete the replacement? | Go to Step 20 | -- |
20 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
