P003C: A Camshaft Profile Actuator A Control Performance/Stuck Off Bank 1

The camshaft profile actuator A switches the intake camshaft (camshaft A) on bank 1 between fixed cam profiles, usually a low-lift base profile and a high-lift profile. In most designs the unactuated state ("off") is the base profile; which profile counts as "on" is defined by the manufacturer. The control module does not need a position sensor to check the switchover: it detects the actual profile indirectly, for example from oil pressure in the switching gallery, intake pressure per cylinder or crankshaft speed fluctuations. This code is set when the switchover is commanded but the camshaft stays on the base profile, or switches too slowly or incompletely. The engine then lacks power at higher engine speed.

Medium severity. Can I keep driving?Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

Bank 1 is the side of the engine with cylinder 1. Inline engines only have this bank.

Symptoms

Check engine light on
Lack of power at higher engine speed
Reduced power mode on some vehicles

Most likely causes

Oil level too low, wrong viscosity or sludged oil, so switching pressure is missing
Profile switching solenoid sticking or its screen clogged
Oil supply to the switching elements leaking or restricted, e.g. worn seals
Locking pin in tappet or rocker arm, or sliding cam piece, sticking
Consequence of a circuit fault of the same actuator

What to check, in order

Start with the simplest. You can tick off each step.

Check the oil level and condition before anything else
Compare the reading with other engine data while varying the engine speed.
Check the solenoid valve's connector
Compare commanded and actual angles in live data
Test the solenoid valve and its filter, if it has one
Check the engine timing if there is chain noise

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P003C means

P: Powertrain: engine and transmission
0: Generic code: same on every make
0: Subsystem depends on the code range
3C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P003C?

Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

What causes code P003C?

The most common causes are: oil level too low, wrong viscosity or sludged oil, so switching pressure is missing; profile switching solenoid sticking or its screen clogged; oil supply to the switching elements leaking or restricted, e.g. worn seals.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.