Diagnostic Aids

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The condition may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Inspect the air delivery system for the following conditions:
- An obstruction to the airflow
- Air leaks
- Misaligned air ducts
- Broken or binding linkages or doors
If the scan tool indicates that the Door Actual parameter is 5-10 counts from the Commanded Door parameter, then perform the recalibration procedure for the HVAC door actuators. Refer to Re-Calibrating Actuators (Primary) or Re-Calibrating Actuators (Auxiliary HVAC) .

Air Recirculation Malfunction

Step	Action	Yes	No
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: Air recirculation is inoperative or is always ON.
1	Did you perform the HVAC Diagnostic System Check?	Go to Step 2	Go to Diagnostic System Check - HVAC Systems - Automatic
2	Turn ON the ignition, with the engine OFF. With a scan tool observe the Recirculate Switch Parameter. Activate the recirculation switch. Does the scan tool indicate that the Recirculate Switch Parameter changes state?	Go to Diagnostic Aids	Go to Step 3
3	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 in Wiring Systems. Did you find and correct the condition?	Go to Step 5	Go to Step 4
4	Replace the HVAC control module. Refer to HVAC Control Module Replacement . Did you complete the replacement?	Go to Step 5	-
5	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 2