NO.23 A/C DOES NOT WORK SUFFICIENTLY [13B-MSP]


id0103f2802900

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 charging amount
•  Open A/C magnetic clutch
•  Open circuit 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 between A/C switch and PCM through both refrigerant pressure switch and A/C amplifier

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Connect the M-MDS to the DLC-2.
Turn the ignition switch to the ON position (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
2
Disconnect the A/C compressor connector.
Start the engine and turn the A/C switch on.
Is there correct voltage at the terminal of the A/C compressor magnetic clutch connector?
Specification
10.5 V or more
Yes
Inspect for GND condition of magnetic clutch on the A/C compressor.
If the GND condition is normal, inspect for an open circuit in the magnetic clutch coil.
No
Go to the next step.
3
Disconnect the refrigerant pressure switch connector.
Connect the jumper wire between the terminals of the A/C high pressure switch connector.
Connect the jumper wires between the terminals of the refrigerant pressure switch connector.
Turn the ignition switch to the ON position.
Turn the A/C switch on and set the blower fan to any speed.
Does the A/C work?
Yes
Inspect the refrigerant pressure switch operation.
If the switch is normal, go to the next step.
No
Inspect for the following:
•  The A/C switch is stuck open.
•  Open circuit between refrigerant pressure switch and PCM terminal 1AU
•  Open circuit between blower motor fan switch and resistor (if blower motor does not operate)
•  Evaporator temperature sensor and A/C amplifier
4
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 whether the A/C relay is stuck open.
Replace if necessary.
No
Inspect the following and repair or replace if necessary:
•  Refrigerant charging amount
•  A/C compressor for seizure
5
•  Verify test results.
―  If normal, return to the diagnostic index to service any additional symptoms.
―  If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.