Troubleshooting

DTC P1012 OCV FOR VVTL CLOSE MALFUNCTION (BANK 1)

CIRCUIT DESCRIPTION

DTC Detecting Condition:

In order to improve the engine performance at both high and low engine speed, the VVTL-i system varies valve lift using the standard cam and high-lift cam. This provides the high power engine performance as well as an emissions reduction and good fuel economy.

When the engine speed reaches 6,000 rpm, the ECM signals the OCV for VVTL-i to switch the effective cam from standard one to high-lift one hydraulically.

The ECM controls the OCV to apply hydraulic pressure to the piston in the rocker arm and switches the rocker arm by locking the slipper for high speed.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

When the engine RPM is high, the VVTL-i actuator advances shims under the high-lift cam followers using engine oil pressure. Switching to the high-lift cam increases the valve lift as well as the intake air volume and exhaust capacity. These changes increase the engine's power output.

When the engine RPM is 6,500 rpm or more, the ECM increases the OCV control signal duty-ratio and it opens the oil passage to VVTL-i actuator. The engine oil pressure powered actuator advances the cam follower shims and valves begin using the high-lift cam.

The VVTL-i oil pressure switch senses the engine oil pressure applied to the VVTL-i system and the ECM judges which cam (standard cam or high-lift cam) is used based on the switch output. If the engine oil pressure applied to the VVTL-i system is high when the standard cam is required by the ECM or if the pressure is low when the high-lift cam is required, the ECM will determine that there is malfunction OCV for VVTL and set a DTC.

Wiring Diagram:

INSPECTION PROCEDURE

Step 1:

Step 2 - 3:

Step 4 - 5:

Hand-held tester

Step 1:

Step 2 - 4:

Step 4 (Continued):

OBD II scan tool (excluding hand-held tester)