P03F4
- Powertrain
- Generic (SAE)
- Emissions
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
B Camshaft Profile Actuator C Control Performance/Stuck Off (Bank 1)
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
Cam profile actuator B position C is electrically OK but does not engage when commanded. The cam phaser actuator adjusts intake/exhaust timing under load — a stuck or slow phaser kills mid-rpm torque and can throw correlation codes between cam and crank.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- No
- Check engine light
- Solid
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Many vehicles show no symptom at all beyond the warning light. The absence of a symptom does not mean the fault is not real.
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | Lock pin or oil supply restricted | Very common | — |
| 2 | Carbon or debris buildup preventing free movement | Occasional | — |
| 3 | Component wear with age - mechanical play | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Camshaft Position Actuator
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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