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Monday, November 8, 2010

How to Check P0021 Camshaft Position-Timing Over-Advanced

How to Check P0021 Camshaft Position Timing Over Advanced

 

How to Check P0021 Camshaft Position Timing Over Advanced

 

 

 

Study Guide

Auto repair

Study and Component Location

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Study and General Description

Study Guide The CVVT (Continuously Variable Valve Timing) system is installed to the chain sprocket of the intake camshaft. This system controls the intake camshaft to provide the optimal valve timing for every driving condition.Study The ECM controls the Oil Control Valve(OCV), based on the signals output from mass air flow, throttle position and engine coolant temperature. The CVVT controller regulates the intake camshaft angle using oil pressure through the OCV. As result, the relative Study position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, exhaust emissions decrease under overall driving conditions.

Study and DTC Description

If there is a delay between the target angle and the real angle over 5 times,ECM sets DTC P0021.

DTC Detecting Condition

Item

Detecting Condition

Possible Cause

DTC Strategy

Study Guide

Slow response check

Poor connection

Contamination of Oil / Clog of Oil path

OCV

CVVT

Enable Conditions

Study Guide

 

Time after | target VVT angle –VVT angle | > 6 deg(2 sec)

Time after engine start > 10 ~ 60 sec

Coolant temperature : 0~120°C

Engine oil temperature : 0~130°C

1000 < rpm < 6600rpm

Threshold value

Study Guide

Counter of delayed following target valve timing > 5 times

Diagnosis Time

-

MIL On Condition

2 Driving Cycles

Specification

OCV

Specification

Coil Resistance (Ω)

6.7 ~ 7.7 (20°C)

Study Guide and Auto Repair

Signal Waveform & Data

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Fig.1) Normal waveform of OCV & IN-CMPS at idle. Study Guide

Fig.2) Normal waveform of OCV & IN-CMPS at acceleration with load.Study Guide

more info and trouble shooting

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