NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZ-CD 1.6 (Y6)]

id0103b3802900

23

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

•  The A/C compressor magnetic clutch does not engage when the A/C switch is turned on.

POSSIBLE CAUSE

•  Improper refrigerant charge amount

•  Open A/C switch magnetic clutch

•  Open circuit between A/C relay and A/C magnetic clutch

•  Poor GND of A/C magnetic clutch

•  Improper A/C magnetic clutch clearance

•  Refrigerant pressure switch is stuck open

•  A/C relay is stuck open

•  Improper A/C cut-off control

•  Open circuit between A/C switch and PCM through both refrigerant pressure switch and A/C amplifier

23	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	• The A/C compressor magnetic clutch does not engage when the A/C switch is turned on.
POSSIBLE CAUSE	• Improper refrigerant charge amount • Open A/C switch magnetic clutch • Open circuit between A/C relay and A/C magnetic clutch • Poor GND of A/C magnetic clutch • Improper A/C magnetic clutch clearance • Refrigerant pressure switch is stuck open • A/C relay is stuck open • Improper A/C cut-off control • Open circuit between A/C switch and PCM through both refrigerant pressure switch and A/C amplifier

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	Perform the self-test function using the M-MDS. Turn the engine switch to the ON position. Retrieve any DTC. Are DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test. Communication error message is displayed: Inspect for the following: • Open circuit between PCM control relay and PCM terminal 236 or 231 • Open circuit between PCM control relay and PCM terminal 241 • PCM control relay stuck open • Open or poor ground circuit (PCM terminal 307, 308 or 332) • Poorly connected vehicle body ground
1		Yes	No DTC is displayed: Go to the appropriate DTC test.
2	Disconnect the A/C compressor connector. Start the engine and turn the A/C switch to on. Is there correct voltage at terminal of A/C compressor magnetic clutch connector? Specification More than 10.5 V	Yes	Inspect for ground condition of the magnetic clutch on the A/C compressor. If the ground condition is normal, inspect the magnetic clutch coil for open circuit.
2		No	Go to the next step.
3	Disconnect the refrigerant pressure switch connector. Connect the jumper wire between terminals of refrigerant pressure switch connector. Turn the engine switch to the ON position. Turn the A/C switch on and set the blower fan at any speed. Measure the PCM terminal 303 voltage. Is the voltage below 1.0 V?	Yes	Inspect the refrigerant pressure switch operation. If the switch is normal, go to the next step.
3		No	Inspect for the following: • A/C switch is stuck open • Open circuit between refrigerant pressure switch and PCM terminal 303 • Open circuit of blower motor fan switch and resistor (if blower motor does not operate) • Evaporator temperature sensor and A/C amplifier
4	Inspect A/C cut-off operation. Does the A/C cut-off operate properly?	Yes	Go to the next step.
4		No	Repair or replace malfunctioning part according to the A/C cut-off system inspection results.
5	Remove the jumper wire 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 the A/C relay for stuck open. Replace if necessary.
5		No	Inspect the following and repair or replace if necessary: • Refrigerant charging amount • Seized A/C compressor
6	Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZ-CD 1.6 (Y6)].) • If the malfunction remains, inspect related Service Information and perform repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)