Test Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

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 A/C 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 a 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 Hot In Vehicle - Auxiliary (Step 1 To 6)
Courtesy of GENERAL MOTORS CORP.

Fig 2: Diagnosis Procedure Too Hot In Vehicle - Auxiliary (Step 7 To 12)
Courtesy of GENERAL MOTORS CORP.

Fig 3: Diagnosis Procedure Too Hot In Vehicle - Auxiliary (Step 13 To 19)
Courtesy of GENERAL MOTORS CORP.

Fig 4: Diagnosis Procedure Too Hot In Vehicle - Auxiliary (Step 20 To 28)
Courtesy of GENERAL MOTORS CORP.

Fig 5: Diagnosis Procedure Too Hot In Vehicle - Auxiliary (Step 29 To 32)
Courtesy of GENERAL MOTORS CORP.