NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR-CD (RF Turbo)]


BME010300103294

23

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

• A/C compressor magnetic clutch does not engage when 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 self-test function using the WDS or equivalent.
Turn the engine switch to the ON position.
Retrieve any DTC.
Is DTC displayed?
Yes

DTC is displayed:

Go to the applicable DTC inspection.

Communication error message is displayed:

Inspect for the following:
• Open circuit between PCM control relay and PCM terminal 53 or 79
• Open circuit PCM control relay and PCM terminal 69
• PCM control relay stuck open
• Open or poor GND circuit (PCM terminal 65, 85, 103 or 104)
• Poor connection vehicle body GND
Yes

No DTC is displayed:

Go to the applicable DTC inspection.
2
Disconnect the A/C compressor connector.
Start the engine and turn the A/C switch on.
Is there correct voltage at terminal of the A/C compressor magnetic clutch connector?

Specification

More than 10.5 V

Yes
Inspect for GND condition of magnetic clutch on the A/C compressor.
If GND condition is normal, inspect the magnetic clutch coil for open circuit.
No
Go to the next step.
3
Disconnect refrigerant pressure switch connector.
Connect a jumper wire between terminals of the 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 voltage of PCM terminal 84.
Is the voltage below 1.0 V?
Yes
Inspect the refrigerant pressure switch operation.
If the switch is normal, go to the next step.
No
Inspect for the following:
• A/C switch is stuck open
• Open circuit between refrigerant pressure switch and PCM terminal 84
• Open circuit of blower motor fan switch and resistor (if blower motor does not operate)
• Evaporator temperature sensor and A/C amplifier
4
Inspect the A/C cut-off operation.
Does the A/C cut-off work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the A/C cut-off system inspection results.
5
Remove a jumper wire from the switch connector.
Reconnect 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.
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.
• If malfunction remains, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR-CD (RF Turbo)].)