DIAGNOSTIC PROCEDURE
NO.23 A/C DOES NOT WORK SUFFICIENTLY (MZI-3.7) DIAGNOSTIC PROCEDURE
POSSIBLE
CAUSE
z
Open the A/C magnetic clutch
z
Open circuit in wiring harness between A/C relay and A/C magnetic clutch
z
Poor GND of A/C magnetic clutch
z
Refrigerant pressure switch is stuck open.
z
A/C relay is stuck open.
z
Seized A/C compressor
z
Open circuit in wiring harness between A/C switch and PCM through both
refrigerant pressure switch and A/C amplifier
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
DTC is displayed:
Go to the appropriate DTC inspection.
(See
DTC TABLE [MZI-3.7]
.)
No
No DTC is displayed:
Go to the next step.
2
Disconnect A/C compressor
connector.
Start engine and turn A/C switch
on.
Is there correct voltage at A/C
compressor magnetic clutch
terminal?
Specification
10.5 V or more
Yes
Inspect for GND condition of magnetic clutch on
A/C compressor.
If GND condition is normal, inspect for open circuit
magnetic clutch coil.
No
Go to the next step.
3
Disconnect refrigerant pressure
switch connector.
Connect jumper wiring between
A/C high pressure switch
terminal.
Connect jumper wiring between
refrigerant pressure switch
terminal.
Turn the ignition switch to the
ON position.
Turn A/C switch on and set
blower fan to any speed.
Does A/C work?
Yes
Inspect refrigerant pressure switch operation.
If switch is normal, go to the next step.
No
Inspect for the following:
z
A/C switch is stuck open.
z
Open circuit in wiring harness between
refrigerant pressure switch and PCM terminal
1R
z
Open circuit in wiring harness between
blower motor fan switch and resistor (if
blower motor does not operate)
z
Evaporator temperature sensor and A/C
amplifier
Remove jumper wiring from the
switch connector.
Yes
Inspect whether A/C relay is stuck open.
Replace if necessary.
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:06 AM
Page 82
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