Mazda CX-9 Grand Touring 2009 Manual page 904

2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9
DTC P0021 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
DTC P0021 CMP timing over-advanced (LH)
DETECTION
CONDITION
POSSIBLE
CAUSE
DIAGNOSTIC PROCEDURE
DTC P0021 (MZI-3.7) DIAGNOSTIC PROCEDURE
STEP
VERIFY FREEZE FRAME DATA HAS
BEEN RECORDED
1
Has FREEZE FRAME DATA been
recorded?
VERIFY RELATED REPAIR
INFORMATION AVAILABILITY
Verify related Service Bulletins and/or
2
on-line repair information availability.
Is any related Service Bulletins
available?
VERIFY TIMING CHAIN
INSTALLATION
Stop the engine.
Remove the front cover.
3
Is the camshaft timing mark at the
correct point?
(See TIMING CHAIN
REMOVAL/INSTALLATION
[MZI-3.7] .)
INSPECT OCV (LH)
Inspect the OCV (LH).
4
(See OIL CONTROL VALVE
(OCV) INSPECTION [MZI-3.7] .)
Is there any malfunction?
2008 Mazda CX-9 Grand Touring
The PCM monitors the variable valve timing position for an over-advanced
camshaft timing. The test fails when the camshaft timing exceeds a maximum
calibrated value or remains in an advanced position.
OCV (LH) malfunction
Spool valve in OCV (LH) is stuck in advanced position
Improper valve timing due to timing chain slippage
INSPECTION ACTION
Yes Go to the next step.
Record FREEZE FRAME DATA on the repair
No
order, then go to the next step.
Perform repair or diagnosis according to the
available Service Bulletins.
Yes
If the vehicle is not repaired, go to the
next step.
No Go to the next step.
Yes Go to the next step.
No Reinstall the timing chain, then go to Step 5.
Replace the OCV (LH), then go to the next step.
Yes (See OIL CONTROL VALVE (OCV)
REMOVAL/INSTALLATION [MZI-3.7] .)
No Go to the next step.