Pinpoint Test B : P0645:00

B1 CHECK THE VOLTAGE TO THE A/C CLUTCH RELAY

Ignition OFF.

Disconnect: A/C Clutch Relay.

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
A/C Clutch Relay Socket Pin 2 Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	GO to B2.
No	VERIFY BJB fuse 70 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short.

B2 CHECK THE A/C CLUTCH RELAY
- Carry out the Relay - Ultra Micro ISO component test on the A/C clutch relay. Refer to OEM WIRING DIAGRAMS COMPONENT TESTING for component testing.
Did the relay pass the component test?

Yes GO to B3.

No INSTALL a new A/C clutch relay.

B3 CHECK THE A/C CLUTCH RELAY COIL SWITCHED GROUND CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect: PCM C175B (3.5L Ti-VCT), C1381B (2.0L GTDI), or C1551B (3.5L GTDI).

Ignition ON.

Measure:

3.5L Ti-VCT engine

Positive Lead	Measurement / Action	Negative Lead
C175B-12	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

2.0L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
C1381B-10	Courtesy of FORD MOTOR COMPANY	Ground

3.5L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
C1551B-2	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.
No	GO to B4.

B4 CHECK THE A/C CLUTCH RELAY COIL SWITCHED GROUND CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Measure:

3.5L Ti-VCT engine

Positive Lead	Measurement / Action	Negative Lead
C175B-12	Courtesy of FORD MOTOR COMPANY	Ground

Measure:

2.0L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
C1381B-10	Courtesy of FORD MOTOR COMPANY	Ground

3.5L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
C1551B-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 CLUTCH RELAY COIL SWITCH GROUND CIRCUIT FOR AN OPEN

Measure:

3.5L Ti-VCT engine

Positive Lead	Measurement / Action	Negative Lead
A/C Clutch Relay Socket Pin 1 Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY	C175B-12

Measure:

2.0L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
A/C Clutch Relay Socket Pin 1 Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY	C1381B-10

Measure:

3.5L GTDI engine

Positive Lead	Measurement / Action	Negative Lead
A/C Clutch Relay Socket Pin 1 Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY	C1551B-2

Is the resistance less than 3 ohms?

Yes	GO to B6.
No	REPAIR the circuit.

B6 CHECK FOR CORRECT PCM 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

Reconnect the 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 TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, INSTALL a new PCM. REFER to Electronic Engine Controls - 2.0L GTDI, REFER to Electronic Engine Controls - 3.5L GTDI or REFER to Electronic Engine Controls - 3.5L Ti-VCT.
No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.