Too Hot in Vehicle. HUMMER H3 2007

For 1990-2009 cars only

Makes 🢒 HUMMER 🢒 2007 🢒 H3 🢒 HVAC 🢒 HVAC - Manual 🢒 Too Hot in Vehicle

Test Description

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

The HVAC control module is inoperative when the module does not respond to an operator control request.

If the condition does not occur when an A/C request has been made, then you must bypass the A/C performance test procedures.

These actions are the enable criteria for the A/C compressor to operate. Ambient air temperature must be above 3°C (38°F) in order for this A/C compressor test to be run.

Performing the Air Conditioning System Performance Test ensures that the A/C system is operating properly for further testing.

If no condition is found with all conditions listed, then compare door travel to a known good vehicle.

Step

Action

Values

Yes

Schematic Reference: HVAC Schematics

DEFINITION: The temperature cannot be adjusted, or the cooling is insufficient during A/C operation.

Did you review the HVAC operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

Turn ON the ignition, with the engine OFF.
Place the blower motor switch in each speed position.

Does the blower motor operate at all?

Go to Step 3

Go to Blower Motor Malfunction

Does the blower motor operate correctly for each speed position?

Go to Step 4

Go to Blower Motor Malfunction

Is the HVAC control assembly inoperative?

Go to Step 15

Go to Step 5

Does the Too Hot in Vehicle concern occur when A/C cooling is desired?

Go to Step 6

Go to Step 8

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 A/C request switch in the ON position.
Place the air temperature switch in the coldest position.

Does the A/C compressor operate?

Go to Step 7

Go to HVAC Compressor Clutch Does Not Engage

Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test .

Did you find and correct the condition?

Go to Step 22

Go to Step 8

Observe the drive shaft of both air temperature actuators.
Adjust the air temperature switch.

Does the drive shaft of both air temperature actuators rotate?

Go to Step 9

Go to Step 10

Inspect the appropriate air temperature door and the appropriate air temperature actuator for the following conditions:

•	A misaligned air temperature actuator.

•	Broken linkages or binding linkages

•	A broken air temperature door or a binding 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 22

Go to Testing for Intermittent Conditions and Poor Connections

Test the position signal circuit of the appropriate temperature actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 11

Test the low reference circuit of the appropriate temperature actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 12

Test the 5-volt reference circuit of the appropriate temperature actuator for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 13

Turn OFF the ignition.
Reconnect the appropriate temperature actuator.
Turn ON the ignition with the engine OFF.
Connect a test lamp between temperature door control A and temperature door control B circuits of the appropriate temperature actuator connector.
Place the temperature switch in the cold position.
Place the mode switch in the hot position.

Does the test lamp illuminate in both positions?

Go to Step 17

Go to Step 14

Test the temperature door control A and temperature door control B circuits of the appropriate temperature actuator for an open, a high resistance, a short to ground, or a short to voltage. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 19

Test the ignition 3 voltage circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 16

Test the ground circuit of the HVAC control module for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 22

Inspect for poor connections at the harness connector of the appropriate air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 18

Inspect the appropriate air temperature actuator, the door, and any attaching linkage for binding or for a condition that prevents drive shaft rotation.

Did you find and correct the condition?

Go to Step 22

Go to Step 20

Inspect for poor connections at the harness connector of the HVAC control assembly. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs .

Did you find and correct the condition?

Go to Step 22

Go to Step 21

Important: Perform the calibration procedure for the air temperature actuator.

Replace the appropriate air temperature actuator. Refer to Temperature Valve Actuator Replacement - Right Side Temperature Valve Actuator Replacement - Left Side .

Did you complete the replacement?

Go to Step 22

Important: Perform the calibration procedure for the HVAC control assembly.