step.
4
Connect the M-MDS to the DLC-2.
Access AC_REQ PID.
Start the engine and idle it.
Turn the A/C switch and fan switch on.
Does AC_REQ PID read on?
Yes
Go to the next step.
No
Inspect the following:
z
Refrigerant pressure switch
operation
z
The A/C switch is stuck open.
z
Open or short circuit between
refrigerant pressure switch and
PCM terminal 1R
z
Open circuit of blower motor
fan switch and resistor (if
blower motor does not
operate)
z
The evaporator temperature
sensor and A/C amplifier
5
Inspect cooling fan control system
operation.
(See
ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.5]
.)
Does the cooling fan control system
function properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning
part.
6
Is the drive belt normal?
Yes
Go to the next step.
No
Replace the drive belt.
7
Is there leakage around the heater unit in
passenger compartment?
Yes
Inspect and service heater for
leakage.
No
Go to the next step.
8
Is there leakage at the coolant hoses and/or
radiator?
Yes
Replace the malfunctioning part.
No
Go to the next step.
9
Cool down the engine.
Remove thermostat and inspect operation.
(see
THERMOSTAT
REMOVAL/INSTALLATION [MZI-
3.5]
.)
(see
THERMOSTAT INSPECTION
[MZI-3.5]
.)
Is thermostat normal?
Yes
The engine coolant temperature and
thermostat are normal, inspect
engine block for leakage or
blockage.
No
Access ECT PID.
Inspect for both ECT PID and
temperature gauge readings.
If temperature gauge on instrument
cluster indicates normal range but
ECT PID is not same as temperature
gauge reading, inspect CHT sensor.
If temperature gauge on instrument
cluster indicates overheating but
ECT PID is normal, inspect
2007 Mazda CX-9 Grand Touring
2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
Microsoft
Sunday, November 15, 2009 9:27:37 AM
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