NO.23 A/C DOES NOT WORK SUFFICIENTLY [YF (2.0L Zetec)]


23	A/C DOES NOT WORK SUFFICIENTLY.
DESCRIPTION	A/C compressor magnetic clutch does not engage when the A/C switch is turned on.
POSSIBLE CAUSE	• Improper refrigerant charging amount • Open circuit in A/C magnetic clutch • Open circuit in wiring harness between A/C relay and A/C magnetic clutch • Poor GND of A/C magnetic clutch • Refrigerant pressure switch is stuck open. • A/C relay is stuck open. • Seized A/C compressor • Open circuit in wiring harness between A/C switch and PCM through both refrigerant pressure switch and A/C amplifier


STEP	INSPECTION	RESULTS	ACTION
1	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs using the WDS or equivalent. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
1		No	No DTC is displayed: Go to the next step.
2	Disconnect the A/C compressor connector. Start the engine and turn A/C switch on. Is the A/C compressor magnetic clutch terminal voltage as specified? Specification More than 10.5 V	Yes	Inspect for GND condition of magnetic clutch on A/C compressor. • If GND condition is normal, inspect for open circuit magnetic clutch coil.
2		No	Go to the next step.
3	Disconnect the refrigerant pressure switch connector. Connect jumper wires between the A/C high-pressure switch terminal. Connect jumper wires between the refrigerant pressure switch terminals. Connect the WDS or equivalent to the DLC-2. Access the ACCS PID. Turn the ignition switch to the ON position. Turn the A/C switch on and set the blower fan at any speed. Does the ACCS PID read "On"?	Yes	Inspect refrigerant pressure switch operation. • If switch is normal, go to the next step.
3		No	Inspect for following: • A/C switch is stuck open. • Open circuit in wiring harness between refrigerant pressure switch and PCM terminal 41 • Open circuit of blower motor fan switch and resistor (if blower motor does not operate) • Evaporator temperature sensor and A/C amplifier
4	Remove the jumper wires from the switch connector. Reconnect the connector to the refrigerant pressure switch. Start the engine and turn the A/C switch on. Does the fan operate?	Yes	Inspect for stuck open A/C relay. Replace if necessary.
4		No	Inspect following and repair or replace if necessary: • Refrigerant charging amount • A/C compressor for being seized
5	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [YF (2.0L Zetec)].) • If any malfunction remains, inspect related service information and, repair or diagnosis accordingly. - If the vehicle is repaired, troubleshooting completed. - If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)