The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
---|---|---|---|---|
Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The A/C compressor clutch will not engage when 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 |
Is the engine coolant temperature (ECT) indicator illuminated? | -- | Go to Engine Coolant Temperature Indicator Always On in Engine Cooling | Go to Step 3 | |
3 |
Important: The ambient air temperature (AAT) must be above 3°C (36°F).
Does the A/C compressor operate? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 4 |
4 |
Are the pressure values within the specifications for the AAT, and within 103 kPa (15 psi) of each other? | -- | Go to Step 5 | Go to Leak Testing |
5 |
Are the high side pressure values within 103 kPa (15 psi) of each other? | -- | Go to Step 6 | Go to Step 19 |
Is the HVAC control assembly inoperative? | -- | Go to Step 10 | Go to Step 7 | |
7 |
Does the scan tool indicate that the A/C request signal is YES? | -- | Go to Step 8 | Go to Step 12 |
8 | With a scan tool, observe the A/C Commanded parameter in the Engine Data 2 list. Does the scan tool indicate that the A/C Commanded parameter is ON? | -- | Go to Step 9 | Go to Step 29 |
9 | With a scan tool, command the A/C compressor clutch relay ON and OFF. Does the A/C compressor clutch relay turn ON and OFF with each command? | -- | Go to Step 13 | Go to Step 15 |
10 | Test the voltage supply circuits to the HVAC control assembly for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 11 |
11 | Test the ground circuit to the HVAC control assembly for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 27 |
12 |
Does the voltage measure near the specified value? | 12 V | Go to Step 28 | Go to Step 17 |
13 |
Does the test lamp illuminate? | -- | Go to Step 14 | Go to Step 22 |
14 |
Does the A/C compressor clutch engage? | -- | Go to Step 25 | Go to Step 18 |
15 |
Does the test lamp illuminate? | -- | Go to Step 16 | Go to Step 21 |
16 |
Does the test lamp turn ON and OFF with each command? | -- | Go to Step 25 | Go to Step 23 |
17 | Test the request signal circuit for a high resistance, an open, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 36 | Go to Step 27 |
18 | Test the A/C compressor clutch supply voltage circuit at the A/C compressor clutch for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 20 |
19 | Test the ground circuit of the A/C pressure sensor for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 24 |
20 | Test the ground circuit of the A/C compressor clutch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 26 |
21 | Repair the coil 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 36 | -- |
22 | 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 36 | -- |
23 | Test the control circuit of the A/C compressor clutch relay for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 29 |
24 | 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 Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 36 | Go to Step 30 |
25 | Inspect for poor connections at the A/C compressor clutch relay. 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 36 | Go to Step 31 |
26 | Inspect for poor connections at the harness connector of the A/C compressor clutch coil. 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 36 | Go to Step 32 |
27 | Inspect for poor connections at the harness connector of the HVAC control assembly. 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 36 | Go to Step 33 |
28 | Inspect for poor connections at the BCM. 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 36 | Go to Step 34 |
29 | Inspect for poor connections at the harness connector of the powertrain control module (PCM). 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 36 | Go to Step 35 |
30 | Replace the A/C high pressure switch. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 36 | -- |
31 | Replace the A/C compressor clutch relay. Did you complete the replacement? | -- | Go to Step 36 | -- |
32 | Replace the A/C compressor clutch coil. Refer to Air Conditioning Clutch Coil Removal and Air Conditioning Clutch Coil Installation in Heating, Ventilation and Air Conditioning. Did you complete the replacement? | -- | Go to Step 36 | -- |
33 | Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Did you complete the replacement? | -- | Go to Step 36 | -- |
34 | 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 36 | -- |
35 | 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 36 | -- |
36 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 4 |