Test Description

WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.

The number below refers to the step number on the diagnostic table.

12: The voltage will vary between 0-12 volts during normal operation. The HVAC control module connector must be connected during this step.

Too Hot in Vehicle

Step	Action	Values	Yes	No
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The temperature cannot be adjusted or the cooling is insufficient during A/C operation.
1	IMPORTANT: Both the left and the right air temperature controls are diagnosed in this table. Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Install a scan tool. Turn ON the ignition, with the engine OFF. Observe the DTC List in Vehicle DTC Information. Does the scan tool display any DTC B0408, B0409, B0414, B0418, B0419 or B0424?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information	Go to Step 3
3	Turn ON the ignition, with the engine OFF. 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	Does the Too Hot in Vehicle concern occur when A/C cooling is desired?	-	Go to Step 6	Go to Step 8
6	IMPORTANT: For A/C compressor operation, the ambient air temperature must be above 3°C (38°F). Start the engine. Place the blower motor switch in the maximum speed position. Place the mode switch in the Bi-Level position. Place the A/C request switch in the ON position. Place both temperature switches in the coldest position. Does the A/C compressor operate?	-	Go to Step 7	Go to HVAC Compressor Clutch Does Not Engage
7	Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation and Air Conditioning. Did you find and correct the condition?	-	Go to Step 18	Go to Step 8
8	Install a scan tool. Observe the Driver Temp Door Position and Passenger Temp Door Position in the HVAC scan tool data list. Adjust the air temperature switch. Does the scan tool indicate the driver and passenger temp data values are within the specified parameter?	0-255 Counts	Go to Step 9	Go to Step 10
9	Inspect the air temperature door and the air temperature actuator for the following conditions: A misaligned air temperature actuator-Refer to Air Temperature Actuator Replacement (Single Zone) . Broken or binding linkages or air temperature door An obstruction that prevents the air temperature door from operating within the full range of motion Missing seals to the air temperature door Misaligned seals to the air temperature door Did you find and correct the condition?	-	Go to Step 18	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
10	Test the door control circuit of the air temperature actuator for the following conditions: An open High resistance A short to ground A short to voltage Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 18	Go to Step 11
11	Test the ground circuit of the air temperature actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 18	Go to Step 12
12	IMPORTANT: Ensure that the HVAC control module connector is connected during this step in order to avoid misdiagnosis. Turn ON the ignition, with the engine OFF. Measure the voltage from the door control circuit of the air temperature actuator to a good ground. Place the air temperature switch from the coldest position to the warmest position. Is the voltage within the specified values with a smooth transition between cold and hot?	0 V at cold 12 V at hot	Go to Step 13	Go to Step 15
13	Inspect for poor connections at the harness connector of the air temperature actuator. 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 18	Go to Step 14
14	Inspect the air temperature door and the air temperature actuator for the following conditions: A misaligned air temperature actuator-Refer to Air Temperature Actuator Replacement (Single Zone) . Broken or binding linkages or air temperature door An obstruction that prevents the air temperature door from operating within the full range of motion Missing seals to the air temperature door Misaligned seals to the air temperature door Did you find and correct the condition?	-	Go to Step 18	Go to Step 16
15	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 18	Go to Step 17
16	Replace the air temperature actuator. Refer to Air Temperature Actuator Replacement - Right (Dual Zone) or Air Temperature Actuator Replacement - Left (Dual Zone) . Did you complete the replacement?	-	Go to Step 18	-
17	Replace the HVAC control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming. 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