HVAC Compressor Clutch Does Not Engage. Chevrolet Malibu 2006

For 1990-2009 cars only

Makes 🢒 Chevrolet 🢒 2006 🢒 Malibu 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 HVAC Compressor Clutch Does Not Engage

HVAC Compressor Clutch Does Not Engage L61

Test Description

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

The A/C compressor relay output is disabled if engine coolant temperature is above 128°C (262°F). The instrument panel engine coolant indicator will indicate overheating.

Place the mode switch in any position except OFF, and place the air temperature control switch in a cold setting. Use the bi-level mode for consistent testing of the A/C system operation.

The HVAC control module is inoperative if the module does not respond to any operator control requests.

Step	Action	Yes	No
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The A/C compressor clutch will not engage if an A/C request has been made, and a Powertrain DTC has not been set.
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Start the engine. Observe the instrument panel coolant temperature indicator and the driver information center. Is the engine coolant temperature indicator indicating an over heat status or is the driver information center indicating low coolant?	Go to Engine Overheating in Engine Cooling	Go to Step 3
3	Important: For A/C compressor operation, the ambient air temperature must be above 4°C (40°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 clutch engage?	Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems	Go to Step 4
4	Open the window in order to ventilate the interior of the vehicle. If the A/C system was operating, then wait for approximately 2 minutes. Turn OFF the ignition. Install the J 43600 ACR 2000 Air Conditioning Service Center. Record the ambient air temperature at the vehicle. Record readings of the low and high side STATIC pressures. Compare the low side pressure values and the high side pressure values with the allowable limits for the recorded ambient air temperature. Refer to Air Conditioning (A/C) System Performance Test . Are the pressure values within the allowable limits for the recorded ambient air temperature, and within 103 kPa (15 psi) of each other?	Go to Step 5	Go to Leak Testing in Heating, Ventilation and Air Conditioning
5	Turn ON the ignition, with the engine OFF. With a DMM, observe the A/C High Side Pressure Sensor Signal Voltage parameter. Compare the DMM A/C High Side Pressure Sensor Signal Voltage parameter to the high side pressure values on the J 43600 . Are the high side pressure values within 103 kPa (15 psi) of each other?	Go to Step 6	Go to Step 23
6	Is the HVAC control module inoperative?	Go to Step 16	Go to Step 7
7	Start the engine. With a scan tool, observe the A/C Request Signal parameter in the powertrain control module (PCM) data list. Place the air temperature switch in the coldest position. Place the A/C request switch in the ON position. Does the scan tool indicate that the A/C Request Signal parameter is YES?	Go to Step 10	Go to Step 8
8	Start the engine. With a scan tool, observe the A/C Switch parameter in the body control module (BCM) data list. Place the air temperature switch in the coldest position. Place the A/C request switch in the ON position. Does the scan tool indicate that the A/C Switch parameter is ON?	Go to Step 9	Go to Step 18
9	Turn OFF the ignition. Test the A/C request signal circuit for a short to voltage, for a high resistance, or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 10
10	With a scan tool, command the A/C compressor clutch relay ON and OFF. Does the clutch relay turn ON and OFF with each command?	Go to Step 14	Go to Step 11
11	Turn OFF the ignition. Disconnect the A/C compressor clutch relay. Turn ON the ignition, with the engine OFF. Probe the coil side of the voltage supply circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate?	Go to Step 12	Go to Step 26
12	Connect a test lamp between the control circuit and the coil side of the voltage supply circuit. With a scan tool, command the A/C compressor clutch relay ON and OFF. Does the test lamp turn ON and OFF with each command?	Go to Step 28	Go to Step 13
13	Does the test lamp remain illuminated with each command?	Go to Step 21	Go to Step 20
14	Turn OFF the ignition. Disconnect the A/C compressor clutch relay. Probe the switch side of the voltage supply circuit with a test lamp that is connected to a good ground. Does the test lamp illuminate?	Go to Step 15	Go to Step 25
15	Connect a 10-amp fused jumper between the switch side voltage circuit of the clutch relay and the supply voltage circuit of the clutch. Turn ON the ignition, with the engine OFF. Does the A/C compressor clutch engage?	Go to Step 28	Go to Step 22
16	Test the ignition 3 voltage circuit of the HVAC control module for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 17
17	Test the ground circuit of the HVAC control module for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 30
18	Start the engine. Place the A/C request in the ON position. Measure the voltage on the request circuit at the BCM to a good ground. Does the value measure near battery voltage?	Go to Step 31	Go to Step 19
19	Test the A/C request signal circuit for a high resistance, open or a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 39	Go to Step 30
20	Test the control circuit of the A/C compressor clutch relay for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 32
21	Test the control circuit of the A/C compressor clutch relay for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 32
22	Test the supply voltage circuit at the A/C compressor clutch for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 24
23	Test the ground circuit of the A/C refrigerant pressure sensor for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 27
24	Test the ground circuit of the A/C compressor clutch for a high resistance or for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 29
25	Repair the switch side voltage supply circuit of the A/C compressor clutch relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 39	--
26	Repair the coil side of the voltage supply circuit of the A/C compressor clutch relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?	Go to Step 39	--
27	Inspect for poor connections at the harness connector of the A/C high pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 33
28	Inspect for poor connections at the A/C compressor clutch relay. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 34
29	Inspect for poor connections at the harness connector of the A/C compressor clutch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 35
30	Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 36
31	Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 37
32	Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 39	Go to Step 38
33	Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation, and Air Conditioning. Did you complete the replacement?	Go to Step 39	--
34	Replace the A/C compressor clutch relay. Did you complete the replacement?	Go to Step 39	--
35	Replace the A/C compressor clutch assembly. Refer to Compressor Clutch Assembly Replacement in Heating, Ventilation, and Air Conditioning. Did you complete the replacement?	Go to Step 39
36	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 39	--
37	Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	Go to Step 39	--
38	Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	Go to Step 39	--
39	Operate the system in order to verify the repair. Did you correct the condition?	System OK	Go to Step 4

HVAC Compressor Clutch Does Not Engage LX9/LZ9

Test Description

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

The A/C compressor relay output is disabled if engine coolant temperature is above 128°C (262°F). The instrument panel engine coolant indicator will indicate overheating.

Place the mode switch in any position except OFF, and place the air temperature control switch in a cold setting. Use the bi-level mode for consistent testing of the A/C system operation.

The HVAC control module is inoperative if the module does not respond to any operator control requests.

Step

Action

Yes

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: The A/C compressor clutch will not engage if an A/C request has been made, and a Powertrain DTC has not been set.

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Start the engine.
Observe the instrument panel (I/P) coolant temperature indicator and the driver information center.

Is the engine coolant temperature indicator indicating an over heat status or is the driver information center indicating low coolant?

Go to Engine Overheating

Go to Step 3

Important: For A/C compressor operation, the ambient air temperature must be above 4°C (40°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 clutch engage?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 4

Open the window in order to ventilate the interior of the vehicle.
If the A/C system was operating, then wait for approximately 2 minutes.
Turn OFF the ignition.
Install the J 43600 ACR 2000 Air Conditioning Service Center.
Record the ambient air temperature at the vehicle.
Record readings of the low and high side STATIC pressures.
Compare the low side pressure values and the high side pressure values with the allowable limits for the recorded ambient air temperature. Refer to Air Conditioning (A/C) System Performance Test .

Are the pressure values within the allowable limits for the recorded ambient air temperature, and within 103 kPa (15 psi) of each other?

Go to Step 5

Go to Leak Testing

Turn ON the ignition, with the engine OFF.
With a scan tool, observe the A/C High Side Pressure Sensor parameter in the powertrain control module data list.
Compare the scan tool A/C High Side Pressure parameter to the high side pressure values on the J 43600 .

Are the high side pressure values within 103 kPa (15 psi) of each other?

Go to Step 6

Go to Step 23

Is the HVAC control module inoperative?

Go to Step 16

Go to Step 7

Start the engine.
With a scan tool, observe the A/C Request Signal parameter in the powertrain control module (PCM) or engine control module (ECM) data list.
Place the air temperature switch in the coldest position.
Place the A/C request switch in the ON position.

Does the scan tool indicate that the A/C Request Signal parameter is YES?

Go to Step 10

Go to Step 8

Start the engine.
With a scan tool, observe the A/C Switch parameter in the body control module (BCM) data list.
Place the air temperature switch in the coldest position.
Place the A/C request switch in the ON position.

Does the scan tool indicate that the A/C Switch parameter is ON?

Go to Step 9

Go to Step 18

Turn OFF the ignition.
Test the A/C request signal circuit for the following:

•	A short to voltage

•	A high resistance

•

An open

Refer to Circuit Testing and to Wiring Repairs.

Did you find and correct the condition?