DTC P0645: A/C Clutch Relay Circuit
NOTE:
For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.
NOTE:
A/C clutch relay may also be referred to as A/C compressor clutch relay. A/C clutch relay circuit is monitored when ignition is on and battery voltage is more than 10 volts. DTC may be stored in Powertrain Control Module (PCM) when PCM detects an open or shorted condition in the A/C clutch relay circuit. Possible causes are: defective A/C clutch relay, fused ignition switch output circuit open, A/C clutch relay control circuit open or shorted, defective PCM, or defective connectors or wiring.
- Turn ignition on with engine off. Using scan tool, actuate A/C clutch relay. Listen for clicking sound at A/C clutch relay. The A/C clutch relay is located in power distribution center at driver's side front corner of engine compartment, near battery. See Fig 1. If clicking sound is heard at A/C clutch relay, go to next step. If no clicking sound is heard at A/C clutch relay, go to step 4.
- Ensure ignition is still on and A/C clutch relay is still actuated by the scan tool. Wiggle wiring harness and connectors from A/C clutch relay to PCM while A/C clutch relay is still actuated. PCM is located between driver's side front fender and power distribution center, near battery. If clicking sound at A/C clutch relay was not interrupted while wiggling wiring harness and connectors, go to next step. If clicking sound at A/C clutch relay was interrupted while wiggling wiring harness and connectors, repair wiring or connectors as necessary. Perform TEST VER-2A .
- Turn ignition off. Inspect wiring harness and connectors between A/C clutch relay and PCM. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary. Perform TEST VER-2A .
- Turn ignition off. Remove A/C clutch relay from power distribution center. See Fig 1. Turn ignition on. Using voltmeter, check voltage at cavity "A" (White/Black wire) for A/C clutch relay in power distribution center. See Fig 1.
- If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open circuit on White/Black wire to A/C clutch relay. White/Black wire goes from A/C clutch relay in power distribution center to Positive Temperature Coefficient (PTC) No. 1 in junction block, located behind driver's side of instrument panel, to the left of steering column. PTC receives voltage when ignition is on. Perform TEST VER-2A .NOTE: PTC is a specified amperage solid-state circuit breaker located in junction box. PTC may reset when all current is removed from PTC for approximately 20 seconds.
- Using ohmmeter, check resistance between terminals No. 85 and 86 on A/C clutch relay. See Fig 2. If resistance is less than 100 ohms, go to next step. If resistance is 100 ohms or more, replace A/C clutch relay. Perform TEST VER-2A .
- Ensure ignition is off. Disconnect connectors at PCM. PCM is located between driver's side front fender and power distribution center, near battery.
- Using ohmmeter, check resistance between ground and PCM connector terminal No. 64 (Dark Blue/Orange wire). If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on Dark Blue/Orange wire between PCM and A/C clutch relay. Perform TEST VER-2A .
- Using ohmmeter, check resistance between cavity "C" (Dark Blue/Orange wire) for A/C clutch relay in power distribution center and PCM connector terminal No. 64 (Dark Blue/Orange wire). See Fig 1.
- If resistance is 5 ohms or more, repair open circuit on Dark Blue/Orange wire between PCM and cavity "C" for A/C clutch relay in power distribution center. Perform TEST VER-2A . If resistance is less than 5 ohms, replace PCM. Perform TEST VER-2A .