P2DEC: Cylinder 3 Intake Valve Lift Range/Performance

What it means

The variable intake valve lift on cylinder 3 does not reach the commanded position within tolerance. Mechanism wear or actuator force degraded.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

A variable-lift mechanism controls how far the intake valve on cylinder 3 opens, and the control module checks the mechanism's position against the commanded lift. This range/performance code sets when cylinder 3's intake lift falls outside the allowed tracking tolerance.

Common causes

Most likely first.

1. Variable lift mechanism worn
2. Oil pressure to actuator low
3. Sensor element aged beyond calibration window

Symptoms

• Check-engine light
• Reduced engine power or acceleration
• Rough idle or engine hesitation

How to diagnose it

1. Read freeze-frame data and review cylinder 3 misfire counts and valve-lift command and position to identify when the mismatch occurs.
2. Check the oil level and condition, since the cylinder 3 actuator may not move correctly if its oil supply is inadequate.
3. Inspect the cylinder 3 actuator and position-sensor wiring and connectors for looseness, damage, or contamination.
4. Use the manufacturer's scan-tool test to command cylinder 3 intake lift and check whether the position reading follows.
5. If the electrical response is normal, test oil supply to the actuator and inspect the cylinder 3 lift mechanism for wear or sticking.

Common fixes

• Restore the engine oil to the specified level and condition.
• Repair damaged wiring or poor connections at the cylinder 3 lift actuator or sensor.
• Replace the cylinder 3 position sensor if it does not pass the specified test.
• Repair or replace the cylinder 3 lift mechanism or actuator if it is worn, binding, or unable to meet the command.

Can I keep driving?

Drive gently and avoid demanding acceleration because cylinder 3 may hesitate or misfire and engine power can fall. Stop if the check-engine light flashes or the engine runs very roughly, as a sustained misfire can harm the catalytic converter.