NO.23 A/C DOES NOT WORK SUFFICIENTLY [L8, LF, L5]


id010346802900

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 the A/C magnetic clutch
•  Open circuit in wiring harness between A/C relay and A/C magnetic clutch
•  Poor ground 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

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Connect the M-MDS to the DLC-2.
Switch the ignition to ON (Engine off).
Retrieve any DTCs.
Are there any DTCs displayed?
Yes
DTC is displayed:
Go to the appropriate DTC inspection.
No
No DTC is displayed:
Go to the next step.
2
Disconnect A/C compressor connector.
Start the engine and turn the A/C switch on.
Is there correct voltage at the A/C compressor magnetic clutch terminal?
Specification
10.5 V or more
Yes
Inspect the ground condition of magnetic clutch on A/C compressor.
If the ground 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 a jumper wire between the A/C high pressure switch terminal.
Connect a jumper wire between the refrigerant pressure switch terminal.
Switch the ignition to ON.
Turn the A/C switch on and the set 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 the following:
•  A/C switch is stuck open.
•  Open circuit in the wiring harness between the refrigerant pressure switch and PCM terminal 1AW
•  Open circuit in the wiring harness between the blower motor fan switch and the resistor (if blower motor does not operate)
•  Evaporator temperature sensor and A/C amplifier
4
Remove 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 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 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.