Pinpoint Test B : P0645

WARNING: This page is about a different car, the 2017 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.

B1 CHECK THE VOLTAGE TO THE A/C (AIR CONDITIONING) CLUTCH RELAY VOLTAGE SUPPLY CIRCUITS

Ignition OFF.

Disconnect A/C clutch relay.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 1	Courtesy of FORD MOTOR COMPANY	Ground

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 3	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages greater than 11 volts?

Yes

GO to B2

No	REFER to the OEM Electrical Wiring Diagram Introduction article to identify the possible causes of the circuit short.

B2 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY
- Carry out the component test on the A/C clutch relay. Refer to OEM WIRING DIAGRAMS COMPONENT TESTING for schematic and connector information.
Does the relay pass the component test?

Yes GO to B3

No INSTALL a new A/C clutch relay.

B3 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect PCM 2.0L C1381B , 2.7L C1551B or 3.5L C175B .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 2	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.

No	GO to B4

B4 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 2	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to B5

No	REPAIR the circuit.

B5 CHECK THE A/C (AIR CONDITIONING) CLUTCH RELAY CONTROL CIRCUIT FOR AN OPEN

Measure:

2.0L

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 2	Courtesy of FORD MOTOR COMPANY	C1381B-2

2.7L

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 2	Courtesy of FORD MOTOR COMPANY	C1551B-2

3.5L

Positive Lead	Measurement / Action	Negative Lead
A/C clutch relay socket 2	Courtesy of FORD MOTOR COMPANY	C175B-15

Is the resistance less than 3 ohms?

Yes

GO to B6

No	REPAIR the circuit.

B6 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all PCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Connect all PCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new PCM. Refer to POWERTRAIN CONTROL MODULE (PCM) - 2.0L EcoBoost (184kW/250PS) - MI4. REFER to: POWERTRAIN CONTROL MODULE (PCM) - 2.7L EcoBoost (238kW/324PS). REFER to: POWERTRAIN CONTROL MODULE (PCM) - 3.5L Duratec (212kW/278PS).

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.