NO.12 LACK/LOSS OF POWER-ACCELERATION/CRUISE (MZI-3.7) DIAGNOSTIC PROCEDURE
STEP
INSPECTION
RESULTS
ACTION
1
Verify the following:
z
Vacuum connection
z
Restriction in intake-air system (such
as air cleaner element, fresh air duct)
z
No air leakage from intake-air system
z
No restriction of intake-air system
z
Proper sealing of intake manifold and
components attached to intake
manifold
z
Fuel quality (such as proper octane,
contamination, winter/summer blend)
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
Is the engine overheating?
Yes
Go to symptom troubleshooting "No. 17
Cooling system concerns-Overheating".
No
Go to the next step.
4
Connect the M-MDS to the DLC-2.
Access APP1, APP2, APP3, RPM, MAF,
TP1, TP2, IAT and VSS PIDs.
Drive vehicle while monitoring PIDs.
Are PIDs within specifications?
(See
PCM INSPECTION [MZI-3.7]
.)
Yes
Go to the next step.
No
APP1, APP2, APP3 PIDs:
Inspect if output signal accelerator pedal
position sensor changes smoothly.
RPM PID:
Inspect CKP sensor and related wiring
harness for vibration or intermittent
open/short circuit or both.
MAF PID:
Inspect for intermittent open circuit of
MAF sensor and related wiring harness.
TP1, TP2 PID:
Inspect if output signal TP sensor changes
smoothly.
IAT PID:
Inspect for air suction in intake-air
system.
If normal, inspect intermittent short circuit
of IAT sensor and related wiring
harnesses.
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 58
© 2005 Mitchell Repair Information Company, LLC.
