NO.23 A/C DOES NOT WORK SUFFICIENTLY [L3]


BME010300000W25

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 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 WDS or equivalent to DLC-2.
Retrieve any continuous memory, KOEO and KOER DTCs.
Are there any DTCs displayed?
Yes

DTC is displayed:

Go to appropriate DTC test.
No

No DTC is displayed:

Go to next step.
2
Disconnect A/C compressor connector.
Start engine and turn A/C switch on.
Is there correct voltage at terminal of A/C compressor magnetic clutch connector?
Specification

More than 10.5 V

Yes
Inspect for GND condition of magnetic clutch on A/C compressor.
If GND condition is okay, inspect for open circuit magnetic clutch coil.
No
Go to next step.
3
Disconnect refrigerant pressure switch connector.
Connect jumper wire between terminals of A/C high pressure switch connector.
Connect jumper wires between terminals of refrigerant pressure switch connector.
Connect WDS or equivalent to DLC-2.
Access ACSW PID.
Turn ignition switch to ON position.
Turn A/C switch on and set blower fan at any speed.
Does ACSW PID read ON?
Yes
Inspect refrigerant pressure switch operation.
If switch is okay, go to next step.
No
Inspect for following:
• A/C switch is stuck open.
• Open circuit between refrigerant pressure switch and PCM terminal 1AC
• Open circuit of blower motor fan switch and resistor (if blower motor does not operate)
• Evaporator temperature sensor and A/C amplifier
4
Remove jumper wire from switch connector.
Reconnect connector to refrigerant pressure switch.
Start engine and turn A/C switch on.
Does fan operate?
Yes
Inspect for stuck open A/C relay.
Replace if necessary.
No
Inspect following and repair or replace as necessary:
• Refrigerant charging amount
• A/C compressor for being seized
5
Verify test results.
• If okay, return to diagnostic index to service any additional symptoms.
• If malfunction remains, replace PCM.