The compressor clutch coil is fed power through the A/C relay. The coil is grounded through CKT 350.
Before you begin to diagnose the problem, correct and clear all DTCs. An open power steering switch or a faulty throttle position sensor may prevent the A/C clutch from engaging.
This step determines whether the A/C relay is receiving power on CKT 2340.
This step determines whether the compressor clutch is faulty. Test for an open in ground CKT 350.
Step | Action | Value(s) | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Did you perform the Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check | |||||||||||
2 |
Is the A/C clutch engaged? | -- | Go to Step 3 | Go to Step 10 | ||||||||||
3 | With the engine idling, connect a Scan Tool . Does the Scan Tool display the A/C request NO? | -- | Go to Step 4 | Go to Step 5 | ||||||||||
4 | Refer to Powertrain Control Power and Ground Check in Engine Controls - 4.0, 4.6L. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
5 | Verify the following Scan Tool readings:
Do the sensors read OK? | -12°C (10°F) | Go to Step 6 | Go to Step 7 | ||||||||||
6 | Replace the heater and A/C programmer. Refer to Programmer Replacement . Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
7 | Test for additional resistance in the sensor wiring caused by a loose or corroded connection. Is the sensor wiring OK? | -- | Go to Step 8 | Go to Step 9 | ||||||||||
8 | Replace the sensor. Refer to Ambient Temperature Sensor Replacement . Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
9 | Repair the faulty sensor wiring. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
10 |
Does the A/C relay cycle? | -- | ||||||||||||
11 |
Is the coil resistance within the specified values? | 70 ohms -150 ohms | Go to Step 12 | Go to Step 15 | ||||||||||
12 | Measure the voltage between harness pin C3 and ground. Is the voltage within the specified range? | 10 -15 V | Go to Step 13 | Go to Step 14 | ||||||||||
13 | Repair the open in the following components:
Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
14 | Repair the open in CKT 339. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | GO to Powertrain Control Power and Ground Check in Engine Controls - 4.0, 4.6L. | ||||||||||
15 | Is the coil resistance greater than the specified value? | 150 ohms | Go to Step 16 | Go to Step 17 | ||||||||||
16 | Replace the relay. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
17 | Is the coil resistance less than the specified value? | 70 ohms | Go to Step 18 | -- | ||||||||||
18 | Replace the A/C relay. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
19 |
Does the clutch engage? | -- | Go to Step 20 | Go to Step 21 | ||||||||||
20 | Replace the A/C relay. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
Move the fused jumper from pin D1 to pin C1. Does the clutch engage? | -- | Go to Step 22 | Go to Step 23 | |||||||||||
22 |
Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
23 | With the jumper still connected, measure the voltage at pin A of the compressor clutch. Is the voltage equal to the battery voltage? | B+ | Go to Step 25 | Go to Step 24 | ||||||||||
24 | Repair the open in CKT 59. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
Test the continuity between pin B of the compressor clutch connectors and ground. Is there continuity? | -- | Go to Step 26 | Go to Step 29 | |||||||||||
26 | Test the A/C compressor clutch coil diode for a short. Is there a short? | -- | Go to Step 27 | Go to Step 28 | ||||||||||
27 | Repair the short in the A/C compressor clutch coil diode. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
28 | Replace the compressor clutch coil. Refer to Air Conditioning Clutch Coil Removal . Did you complete the repair? | -- | Go to Diagnostic System Check | -- | ||||||||||
29 | Repair the open in CKT 350. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Diagnostic System Check | -- |