Rear Window Defogger Inoperative (SUT)
WARNING: This page is about a different car, the 2007 Hummer H2. However, it is still accessible from the selected car via links, so may be relevant.
Rear Window Defogger Inoperative (SUT)
| Step | Action | Yes | No |
|---|---|---|---|
| Schematic Reference: Defogger Schematics Connector End View Reference: Window Systems Connector End Views |
|||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
|
Refer to Liftgate Ajar Indicator Malfunction | Go to Step 3 |
| 3 |
|
Go to Step 4 | Go to Step 11 |
| 4 | Connect a test lamp between the voltage supply side of the rear window defogger grid and a good ground. Does the test lamp illuminate? |
Go to Step 5 | Go to Step 6 |
| 5 | Connect a test lamp between the voltage supply side of the rear window defogger grid and the ground side of the rear window defogger grid. Does the test lamp illuminate? |
Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 13 |
| 6 |
|
Go to Step 7 | Go to Step 9 |
| 7 |
|
Go to Step 12 | Go to Step 8 |
| 8 | Test for an open, high resistance, or short to ground in all of the rear window defogger supply voltage circuits on both sides of the midgate control module. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct a condition? |
Go to Step 18 | Go to Step 10 |
| 9 | Test the battery positive voltage circuit of the DEFOG relay switched input for an open or high resistance. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 14 |
| 10 | Inspect for poor connection at the harness connector of the midgate control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 15 |
| 11 | Inspect for poor connection at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 16 |
| 12 | Inspect for poor connection at the DEFOG relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
Go to Step 18 | Go to Step 17 |
| 13 | Repair an open or high resistance in the ground circuit of the rear window defogger. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 18 | - |
| 14 | Repair a short to ground in the supply voltage circuit of the rear window defogger. Refer to Wiring Repairs
. Did you complete the repair? |
Go to Step 18 | - |
| 15 | Replace the midgate control module. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
Go to Step 18 | - |
| 16 | Replace the HVAC control module. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
Go to Step 18 | - |
| 17 | Replace the DEFOG relay. Refer to Relay Replacement (Attached to Wire Harness)
or Relay Replacement (Within an Electrical Center)
. Did you complete the replacement? |
Go to Step 18 | - |
| 18 | Operate the system in order to verify the repair. Did you correct the condition? |
System OK | Go to Step 2 |