DIAGNOSTIC PROCEDURE
NO.14 POOR FUEL ECONOMY (MZI-3.7) DIAGNOSTIC PROCEDURE
(See BEFORE SERVICE PRECAUTION [MZI-3.7] .)
(See AFTER SERVICE PRECAUTION [MZI-3.7] .)
CAUTION:
z
Disconnecting/connecting quick release connector without cleaning it
may cause damage to fuel pipe and quick release connector. Always
clean quick release connector joint area before
disconnecting/connecting, and make sure that it is free of foreign
material.
STEP
INSPECTION
RESULTS
ACTION
1
Inspect for the following:
z
Air cleaner element for
contamination
z
ATF level
z
Fuel quality
z
Coolant level
z
Brake dragging
Are all items normal?
Yes
Go to the next step.
No
Service if necessary.
Repeat Step 1.
2
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.
3
Access ECT PID.
Drive vehicle while monitoring PID.
(See
PCM INSPECTION [MZI-
3.7]
.)
Is PID within specification?
Yes
Go to the next step.
No
Inspect for coolant leakage, cooling fan and
condenser fan operations or thermostat
operation.
4
Perform the spark test.
(See
ENGINE CONTROL
SYSTEM OPERATION
INSPECTION [MZI-3.7]
.)
Is strong blue spark visible at each
cylinder?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part
according to spark test result.
Install the fuel pressure gauge
Yes
Go to the next step.
Low:
2008 Mazda CX-9 Grand Touring
2008 ENGINE Symptom Troubleshooting (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:10:05 AM
Page 64
© 2005 Mitchell Repair Information Company, LLC.
