DESCRIPTION
The Variable Valve Timing (VVT) system includes the ECM, Oil Control Valve (OCV) and VVT controller. The ECM sends a target "duty-cycle" control signal to the OCV. This control signal, applied to the OCV, regulates the oil pressure supplied to the VVT controller. Camshaft timing control is performed based on engine operation conditions, such as intake air volume, throttle position and engine coolant temperature.
The ECM controls the OCV based on the signals from several sensors. The VVT controller regulates the intake camshaft angle using oil pressure through the OCV. As a result, the relative position between the camshaft and crankshaft is optimized, the engine torque and the fuel economy improve, and the exhaust emission drops. The ECM detects the actual valve timing using signals from the camshaft position sensor and crankshaft position sensor. The ECM then performs feedback control and verifies target valve timing.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0010/39 | Open or short in oil control valve circuit (1 trip detection logic) |
|
MONITOR DESCRIPTION
After the ECM sends the "target" duty-cycle signal to the OCV, the ECM monitors the OCV current to establish an "actual" duty-cycle. The ECM detects a malfunction and sets a DTC when the actual duty-cycle ratio varies from the target duty-cycle ratio.
This monitor runs for 1 second (the first second of engine idle) after the engine is started.
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
When using intelligent tester:
PROCEDURE
PERFORM ACTIVE TEST (OPERATE OCV)
Start and warm up the engine.
Turn the ignition switch OFF.
Connect the intelligent tester to the DLC3.
Turn the ignition switch ON and turn the intelligent tester ON.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Activate the VVT System (Bank 1).
Using the intelligent tester, operate the OCV and check the engine speed.
| OK | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
CHECK FOR INTERMITTENT PROBLEMS |
| NG |
|
CHECK CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (OCV SIGNAL)
Disconnect the C2 OCV connector.
While idling the engine, check the waveform of the OCV connector using the oscilloscope.
| OK | ||||
|---|---|---|---|---|
|
||||
|
| OK |
|
REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY |
| NG |
|
CHECK ECM (OCV SIGNAL)
While idling the engine, check the waveform of the ECM connector using the oscilloscope.
| OK | ||||
|---|---|---|---|---|
|
||||
|
| NG |
|
REPLACE ECM |
| OK |
|
REPAIR OR REPLACE HARNESS AND CONNECTOR
When not using intelligent tester:
PROCEDURE
CHECK CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (OPERATE OCV)
Disconnect the C2 OCV connector.
Apply positive (+) battery voltage between the terminals of the OCV.
Check the engine speed.
| OK |
|---|
| Rough idle or engine stalled. |
| NG |
|
REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY |
| OK |
|
CHECK ECM (OCV SIGNAL)
While idling the engine, check the waveform of the ECM connector using the oscilloscope.
| OK | ||||
|---|---|---|---|---|
|
||||
|
| NG |
|
REPLACE ECM |
| OK |
|
CHECK WIRE HARNESS (CAMSHAFT TIMING OIL CONTROL VALVE (OCV) - ECM)
Disconnect the C2 OCV connector.
Disconnect the E11 ECM connector.
Measure the resistance of the wire harness side connectors.
| Standard resistance | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS AND CONNECTOR |
| OK |
|
CHECK FOR INTERMITTENT PROBLEMS