Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- The condition may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections .
- Inspect the air delivery system for the following conditions:
- A dirty HVAC air filter, if applicable
- An obstruction to the airflow
- Air leaks
- Misaligned air ducts
- Broken or binding linkages or doors
Air Delivery Improper
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views |
||||
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to Diagnostic System Check - Vehicle |
| 2 |
|
- | Go to Step 3 | Go to Blower Motor Always On |
| 3 | Place the blower motor switch in each speed position. Does the blower motor operate in any of the speed positions? |
- | Go to Step 4 | Go to Blower Motor Inoperative |
| 4 | Does the blower motor operate in each speed position? | - | Go to Step 5 | Go to Blower Motor Malfunction |
| 5 |
|
- | Go to Step 6 | Go to Step 7 |
| 6 |
|
- | Go to Diagnostic Aids | Go to Air Recirculation Malfunction |
| 7 | Inspect for poor connections 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 9 | Go to Step 8 |
| 8 | Replace the HVAC control module. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? |
- | System OK | Go to Step 2 |