Mazda CX-9 Grand Touring 2009 Manual page 1022

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9
VERIFY CURRENT INPUT SIGNAL STATUS
(KEY TO ON/IDLE)
Access APP1, APP2, APP3, ECT, IAT, MAF,
RPM TP_REL and VSS PIDs using the M-
4
MDS. (See PCM INSPECTION [MZI-
3.7] .)
Is there any signal that is far out of
specification when the ignition switch is in
the ON position and the engine runs at idle?
VERIFY CURRENT INPUT SIGNAL STATUS
UNDER TROUBLE CONDITION
Inspect the same PIDs as in Step 4 when
5
simulating the FREEZE FRAME DATA
condition.
Is there any signal which causes drastic
changes?
INSPECT SPARK PLUG CONDITION
Turn the ignition switch off.
Remove the spark plug from the suspected
cylinder.
Check the spark plug condition:
6
Cracks
Excess wear
Gap
Wet
Is any problem found on the spark plug?
INSPECT IGNITION SYSTEM OPERATION
FOR SUSPECTED CYLINDER
Perform the spark test for the suspected
7
cylinder. (See ENGINE CONTROL
SYSTEM OPERATION INSPECTION
[MZI-3.7] .)
Are the results of the spark test normal?
INSPECT FUEL INJECTOR WIRING
HARNESS
8
Remove the intake air system parts.
Disconnect the fuel injector connector on the
suspected cylinder.
2008 Mazda CX-9 Grand Touring
Yes
No
Yes
No
Yes
No
Yes Go to the next step.
No
Yes Go to the next step.
Inspect the suspected circuit or part or
both according to inspection results.
Then go to Step 13. (See PCM
INSPECTION [MZI-3.7] .)
Go to the next step.
Inspect the suspected circuit or part or
both according inspection results. Then
go to Step 13. (See PCM INSPECTION
[MZI-3.7] .)
Go to the next step.
If the spark plug is wet, fuel
flooding is suspected. Go to Step
9.
If the spark plug has a crack,
excess wear or improper gap,
replace the malfunctioning spark
plug. Then go to Step 13.
(See CRUISE CONTROL
SWITCH INSPECTION [MZI-
3.7] .)
Go to the next step.
Replace or replace the malfunctioning
part according to the spark test results,
then go to Step 13.
Inspect the fuel injector wiring harnesses.