DTC P0021 (MZI-3.7) DETECTION CONDITIONS AND POSSIBLE CAUSES
DIAGNOSTIC PROCEDURE
DTC P0021 (MZI-3.7) DIAGNOSTIC PROCEDURE
DTC P0021
CMP timing over-advanced (LH)
DETECTION
CONDITION
z
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.
POSSIBLE
CAUSE
z
OCV (LH) malfunction
z
Spool valve in OCV (LH) is stuck in advanced position
z
Improper valve timing due to timing chain slippage
STEP
INSPECTION
ACTION
1
VERIFY FREEZE FRAME DATA HAS
BEEN RECORDED
z
Has FREEZE FRAME DATA been
recorded?
Yes Go to the next step.
No
Record FREEZE FRAME DATA on the repair
order, then go to the next step.
2
VERIFY RELATED REPAIR
INFORMATION AVAILABILITY
z
Verify related Service Bulletins and/or
on-line repair information availability.
z
Is any related Service Bulletins
available?
Yes
Perform repair or diagnosis according to the
available Service Bulletins.
z
If the vehicle is not repaired, go to the
next step.
No
Go to the next step.
3
VERIFY TIMING CHAIN
INSTALLATION
z
Stop the engine.
z
Remove the front cover.
z
Is the camshaft timing mark at the
correct point?
(See
TIMING CHAIN
REMOVAL/INSTALLATION
[MZI-3.7]
.)
Yes Go to the next step.
No
Reinstall the timing chain, then go to Step 5.
4
INSPECT OCV (LH)
z
Inspect the OCV (LH).
(See
OIL CONTROL VALVE
(OCV) INSPECTION [MZI-3.7]
.)
z
Is there any malfunction?
Yes
Replace the OCV (LH), then go to the next step.
(See
OIL CONTROL VALVE (OCV)
REMOVAL/INSTALLATION [MZI-3.7]
.)
No
Go to the next step.
2008 Mazda CX-9 Grand Touring
2008 ENGINE PERFORMANCE On-Board Diagnostic (MZI-3.7) - Mazda CX-9
Microsoft
Sunday, November 15, 2009 10:08:34 AM
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© 2005 Mitchell Repair Information Company, LLC.
