Test Description

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The numbers below refer to the step numbers on the diagnostic table.

2. This step ensures that the primary HVAC system is functioning properly.
3. The DTCs listed could set if a calibration of the actuators is performed.
6. If the condition does not occur when a heating request has been made then you must bypass the A/C compressor and cooling system diagnostic information.
9. This step ensures that the front auxiliary control assembly is providing an auxiliary air temperature input to the auxiliary HVAC control module.
10. This step ensures that the rear seat audio control is providing an auxiliary air temperature input to the auxiliary HVAC control module.
12. When taking temperature reading allow for a 3°C (5°F) temperature variance.
15. When the front auxiliary HVAC control assembly is disconnected, and there is no fault on auxiliary air temperature switch control circuit, the scan tool will read a high count value for the Air Temp. Switch Pos. parameter. A short to ground on circuit will have low count value.

Fig 1: Diagnosis Procedure Too Cold In Vehicle - Auxiliary (Step 1 To 6)
Courtesy of GENERAL MOTORS CORP.

Fig 2: Diagnosis Procedure Too Cold In Vehicle - Auxiliary (Step 7 To 11)
Courtesy of GENERAL MOTORS CORP.

Fig 3: Diagnosis Procedure Too Cold In Vehicle - Auxiliary (Step 12 To 17)
Courtesy of GENERAL MOTORS CORP.

Fig 4: Diagnosis Procedure Too Cold In Vehicle - Auxiliary (Step 18 To 24)
Courtesy of GENERAL MOTORS CORP.

Fig 5: Diagnosis Procedure Too Cold In Vehicle - Auxiliary (Step 25 To 32)
Courtesy of GENERAL MOTORS CORP.