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Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. 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.

  1. 2:  The air conditioning (A/C) compressor relay output is disabled if the engine coolant temperature is above 96°C (205°F).
  2. 3:  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.
  3. 6:  The HVAC control module is inoperative if the module does not respond to any operator control requests.
  4. 23:  The compressor is disabled when the evaporator temperature goes below 3°C (38°F).
  5. 34:  Check the connection by removing and securely reinstalling before replacement of the HVAC control is considered.
HVAC Compressor Clutch Does Not Engage (Hybrid)

Step Action Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
DEFINITION: The air conditioning (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 Vehicle Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Install a scan tool.
  2. Start the engine.
  3. Observe the Engine Coolant Temperature (ECT) parameter in the Engine Control Data General Info-Inputs data list.
Does the scan tool indicate that the ECT parameter is above 96°C (205°F)?		 Go to Engine Overheating Go to Step 3 
3 
IMPORTANT: For A/C compressor operation, the evaporator air temperature must be above 3°C (38°F).
  1. Start the engine.
  2. Place the blower motor switch in the maximum speed position.
  3. Place the A/C request switch in the ON position.
  4. Place the air temperature switch in the coldest position.
Does the A/C compressor operate?		 Go to Testing for Intermittent Conditions and Poor Connections Go to Step 4 
4
  1. Park the vehicle in side or out of direct sunlight.
  2. Open the window in order to ventilate the interior of the vehicle.
  3. If the A/C system was operating, then wait for approximately 2 minutes.
  4. Turn OFF the ignition.
  5. Install the J 43600  ACR 2000 Air Conditioning Service Center.
  6. Record the ambient air temperature at the vehicle.
  7. Record readings of the low and high side STATIC pressures.
  8. Compare the low 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 (L61) or Air Conditioning (A/C) System Performance Test (L66 Red Line) or Air Conditioning (A/C) System Performance Test (L66 Base) or Air Conditioning (A/C) System Performance Test (LAT) .
Are the low and high side 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
5
  1. Turn ON the ignition, with the engine OFF.
  2. With a scan tool, observe the A/C High Side Pressure Sensor parameter in the engine control module (ECM) or powertrain control module (PCM) data list.
  3. Compare the scan tool A/C High Side Pressure parameter to the high side pressure values on the ACR 2000.
Are the high side pressure values within 103 kPa (15 psi) of each other?		 Go to Step 6  Go to Step 24 
6  Is the HVAC control module inoperative? Go to Step 16  Go to Step 7 
7
  1. Start the engine.
  2. With a scan tool, observe the A/C Request Signal parameter in the ECM/PCM data list.
  3. Place the air temperature switch in the coldest position.
  4. 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
  1. Start the engine.
  2. With a scan tool, observe the A/C Request parameter in the body control module (BCM) data list.
  3. Place the air temperature switch in the coldest position.
  4. Place the A/C request switch in the ON position.
Does the scan tool indicate that the A/C Request parameter is ON?		 Go to Step 9  Go to Step 18 
9
  1. Turn OFF the ignition.
  2. Test the A/C request signal circuit for the following:
    • A short to voltage
    • A high resistance
    • An open
Refer to Circuit Testing and Wiring Repairs .Did you find and correct the condition?		 Go to Step 43  Go to Step 10 
10 With a scan tool, command the A/C compressor relay ON and OFF.
Does the A/C compressor relay turn ON and OFF with each command?		 Go to Step 14  Go to Step 11 
11
  1. Turn OFF the ignition.
  2. Disconnect the A/C compressor relay.
  3. Turn ON the ignition, with the engine OFF.
  4. 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 27 
12
  1. Connect a test lamp between the control circuit and the coil side of the voltage supply circuit.
  2. With a scan tool, command the A/C compressor relay ON and OFF in scan tool special functions.
Does the test lamp turn ON and OFF with each command?		 Go to Step 29  Go to Step 13 
13 Does the test lamp remain illuminated with each command? Go to Step 21  Go to Step 19 
14
  1. Turn OFF the ignition.
  2. Disconnect the A/C compressor relay.
  3. 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 26 
15
  1. Connect a 10-amp fused jumper between the switch side voltage circuit of the clutch relay and the supply voltage circuit of the clutch.
  2. Turn ON the ignition, with the engine OFF.
Does the A/C compressor engage?		 Go to Step 29  Go to Step 22 
16 Test the ignition 3 voltage circuit of the HVAC control module for the following:
  • A short to voltage
  • A high resistance
  • An open

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 17 
17 Test the ground circuit of the HVAC control module for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 34 
18
  1. Start the engine.
  2. Place the A/C request in the ON position.
  3. 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 20 
19 Test the control circuit of the A/C compressor relay for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 35 
20 Test the A/C request signal circuit for the following:
  • A short to voltage
  • A high resistance
  • An open

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 23 
21 Test the control circuit of the A/C compressor relay for a short to ground. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 35 
22 Test the supply voltage circuit at the A/C compressor relay for the following:
  • A short to voltage
  • A high resistance
  • An open

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 25 
23  View the evaporator voltage in the BCM scan tool data list under A/C sensor. Refer to Air Temperature Description and Operation  for the evaporator sensor temperature to voltage conversion chart.
Is the Evaporator Voltage parameter greater than the voltage range of 2.45 V-2.55 V which equals a temperature range of 36-38°F?		 Go to Step 24  Go to Step 32 
24 Test the ground circuit of the A/C refrigerant pressure sensor for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 28 
25 Test the ground circuit of the A/C compressor for a high resistance or for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 30 
26 Repair the switch side voltage supply circuit of the relay. Refer to Wiring Repairs .
Did you complete the repair?		 Go to Step 43  -
27 Repair the coil side of the voltage supply circuit of the relay. Refer to Wiring Repairs .
Did you complete the repair?		 Go to Step 43  -
28 Inspect for poor connections at the harness connector of the A/C refrigerant pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 36 
29 Inspect for poor connections at the relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 38 
30 Inspect for poor connections at the harness connector of the A/C compressor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 39 
31 Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 41 
32 Test the evaporator temperature sensor circuits for the following:
  • A short to voltage
  • A high resistance
  • An open

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 33 
33 Inspect for poor connections at the harness connector of the evaporator low temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 34 
34  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 .
Did you find and correct the condition?		 Go to Step 43  Go to Step 37 
35 Inspect for poor connections at the harness connector of the ECM/PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 Go to Step 43  Go to Step 42 
36 Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (L61/L66) or Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement (LAT) .
Did you complete the replacement?		 Go to Step 43  -
37 Replace the evaporator low temperature sensor. Refer to Air Conditioning (A/C) Refrigerant Low Temperature Sensor Replacement .
Did you complete the replacement?		 Go to Step 43  -
38 Replace the relay. Refer to Relay Replacement (Attached to Wire Harness) or Relay Replacement (Within an Electrical Center) .
Did you complete the replacement?		 Go to Step 43  -
39 Replace the A/C compressor. Refer to Compressor Replacement (L61) or Compressor Replacement (L66) or Compressor Replacement (LAT) .
Did you complete the replacement?		 Go to Step 43  -
40 Replace the HVAC control module. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 43  -
41 Replace the BCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 43  -
42 Replace the ECM/PCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 Go to Step 43  -
43 Operate the system in order to verify the repair.
Did you correct the condition?		 System OK Go to Step 4 
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