P2DEF: Cylinder 6 Intake Valve Lift Range/Performance

What it means

The variable intake valve lift on cylinder 6 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

The variable intake valve lift mechanism controls how far the intake valve on cylinder 6 opens, and the control module compares its position signal with the commanded lift. This range/performance code sets when cylinder 6's mechanism does not reach the target within 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. Check freeze-frame data and cylinder 6 misfire counts, then compare live commanded and actual lift to identify when the mismatch appears.
2. Verify engine oil level and condition, because inadequate oil supply can weaken cylinder 6 actuator movement.
3. Inspect the cylinder 6 actuator and position-sensor wiring and connectors for damage, poor contact, or contamination.
4. Command cylinder 6 lift changes with the manufacturer's scan-tool procedure and observe whether the position signal responds.
5. If the circuit checks pass, test oil supply to the actuator and inspect the cylinder 6 lift mechanism for wear or sticking.

Common fixes

• Correct engine oil level or condition to the manufacturer's specification.
• Repair damaged wiring or poor connections at the cylinder 6 lift actuator or position sensor.
• Replace the cylinder 6 position sensor if it fails the specified test.
• Repair or replace the cylinder 6 lift actuator or mechanism if testing confirms wear or binding.

Can I keep driving?

Avoid hard acceleration and limit driving while cylinder 6 lift is not tracking correctly; reduced power and misfiring may worsen. Stop if the check-engine light flashes or the engine becomes severely rough, since ongoing misfire can damage the catalytic converter.