Mazda CX-9 Grand Touring 2007 Manual page 886

2007 ENGINE PERFORMANCE Symptom Troubleshooting (MZI-3.5) - CX-9
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?
5 Inspect cooling fan control system
operation.
(See ENGINE CONTROL SYSTEM
OPERATION INSPECTION [MZI-
3.5].)
Does the cooling fan control system
function properly?
6 Is the drive belt normal?
7 Is there leakage around the heater unit in
passenger compartment?
8 Is there leakage at the coolant hoses and/or
radiator?
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?
2007 Mazda CX-9 Grand Touring
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
Yes
No
step.
Go to the next step.
Inspect the following:
Refrigerant pressure switch
operation
The A/C switch is stuck open.
Open or short circuit between
refrigerant pressure switch and
PCM terminal 1R
Open circuit of blower motor
fan switch and resistor (if
blower motor does not
operate)
The evaporator temperature
sensor and A/C amplifier
Go to the next step.
Repair or replace the malfunctioning
part.
Go to the next step.
Replace the drive belt.
Inspect and service heater for
leakage.
Go to the next step.
Replace the malfunctioning part.
Go to the next step.
The engine coolant temperature and
thermostat are normal, inspect
engine block for leakage or
blockage.
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