Component Location
General Description
The CVVT (Continuously Variable Valve Timing) system is installed to the chain sprocket of the camshafts. This system controls the camshaft to provide the optimal valve timing for whole driving condition. The PCM controls the Oil Control Valve(OCV), based on the signals output from air flow, throttle position and engine coolant temperature. The CVVT controller regulates the camshaft angle using oil pressure through the OCV. As result, the relative position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, exhaust emissions decrease under overall driving conditions.
DTC Description
This diagnosis checks the camshaft position plausibility whether the expected range plus some margin is not violated that might be caused by a wrong engine repair, or a chain/belt misalignment. DTC P0017 is set when actual camshaft position is too much retarded or advanced than full retard position or full advance position. To continue the adjustment in such case could lead to a damage of the engine by hitting the valves with the piston.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Camshaft edge in CVVT full retard position out of Range compared to Reference position
| Valve timing Oil Control Valve CVVT Assembly |
Enable Conditions | Camshaft position adaptation value is valid
|
Threshold Value | Camshaft position adaptation < -15 °CRK
Camshaft position adaptation > +15 °CRK
|
Diagnostic Time | 80 rev.
|
Mil On Condition | 2 Drive Cycles
|
Signal Waveform & Data
Set up an oscilloscope as follows :
Channel A (+): Signal terminal of the CMPS #2(back probe), (-): ground
Channel B (+): Signal terminal of the CKPS(back probe), (-): ground
Start the engine and check for signal waveform compared with reference waveform as below.
A : CMPS and CKPS waveform of exhaust shaft at idle
B : CMPS and CKPS waveform of exhaust cam shaft at acceleration
(Tooth number is changed by CVVT operation)