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 clicking sound is not 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 between A/C clutch relay and 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. Turn ignition on with engine off. Note cavities in power distribution center for A/C clutch relay. See Fig 1 . Using voltmeter, check voltage at cavity No. 86 (White/Black wire) in power distribution center for A/C clutch relay. See Fig 1 .
- If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open on White/Black wire to A/C clutch relay. White/Black wire is the fused ignition switch output and goes from A/C clutch relay in power distribution center to Positive Temperature Coefficient (PTC) No. 1. PTC No. 1 is a specified amperage solid-state circuit breaker which receives voltage when ignition is on and may be reset when all current is removed from PTC for approximately 20 seconds. PTC No. 1 is located in junction block behind driver's side of instrument panel, to left of steering column. Perform TEST VER-2A .
- Turn ignition off. Note which terminals on A/C clutch relay correspond with cavities in power distribution center. See Fig 1 . Using ohmmeter, check resistance between terminals on A/C clutch relay that correspond with cavities No. 85 and 86 in power distribution center. If resistance is 50-90 ohms, go to next step. If resistance is not 50-90 ohms, replace A/C clutch relay. Perform TEST VER-2A .
- Ensure ignition is off and A/C clutch relay is removed from power distribution center. Disconnect PCM connectors. PCM is located between driver's side front fender and power distribution center, near battery.
- Using ohmmeter, check resistance between ground and terminal No. 64 (Dark Blue/Orange wire) on Gray PCM connector C2. 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 cavity No. 85 in power distribution center for A/C clutch relay. Perform TEST VER-2A .
- Note cavities in power distribution center for A/C clutch relay. See Fig 1 . Using ohmmeter, check resistance between cavity No. 85 (Dark Blue/Orange wire) in power distribution center for A/C clutch relay and terminal No. 64 (Dark Blue/Orange wire) on Gray PCM connector C2. If resistance is 5 ohms or more, repair open on Dark Blue/Orange wire between PCM and cavity No. 85 in power distribution center for A/C clutch relay. Perform TEST VER-2A . If resistance is less than 5 ohms, replace PCM. Perform TEST VER-2A .