A Camshaft Position - Timing Over-Retarded Bank 1
What it means
P0012 means the intake camshaft on bank 1 is timed further retarded than the ECM commanded — the variable valve timing (VVT) system isn't advancing the cam correctly. The most common trigger is oil-related: low, dirty, or wrong-grade oil, or a clogged oil control valve, since VVT is driven by oil pressure. Expect rough idle, reduced power, and worse economy until it's corrected.
Can I keep driving? Usually yes, but expect rough running and reduced power; fix it soon since bad cam timing hurts economy and can cause stalling in some cases.
Real-world scan data
Appears alongside · share of P0012 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or occasional stalling
- Reduced power and hesitation
- Increased fuel consumption
- Rattle at start-up (worn phaser)
Common causes
Most likely first
- Low, dirty, or wrong-viscosity engine oil (a leading cause of VVT faults)Likely
- Clogged oil control valve or VVT solenoid screenCommon
- Faulty camshaft oil control (phaser) solenoidCommon
- Stretched timing chain or jumped timingLess often
- Faulty camshaft position sensorLess often
- Failed ECM (rare)Less often
How to diagnose & fix
Work through it in order
- Check oil level and condition first — top up or change with the correct grade.
- Remove and clean or replace the oil control valve/VVT solenoid and its screen.
- Inspect the camshaft position sensor and its wiring.
- Check the timing chain for stretch or a jumped tooth.
- Clear the code and recheck actual cam timing with a scan tool.
P0012 by make
Based on commonly reported failure patterns across owner and repair communities, not on our scan data.
BMW
On BMWs with VANOS variable timing, clogged solenoid screens and low oil are common causes. It can be a relatively simple fix, but do not ignore it since timing problems can get worse.
Chevrolet
On GM engines such as the 3.6L V6, this is commonly linked to a stretched timing chain or worn cam phasers, especially after skipped oil changes. If the engine rattles at startup, get it checked soon.
Ford
Commonly reported on Ford engines with variable cam timing, including the 5.4L three-valve Triton V8. Low or dirty oil and worn cam phasers are frequent causes, so check the oil level and service history first.
GMC
On GMC models with the 3.6L V6, such as the Acadia, this is commonly linked to a stretched timing chain or worn cam phasers, especially after skipped oil changes. If the engine rattles at startup, get it checked soon.
Subaru
On Subarus with variable valve timing, this is often an oil control valve or a sludge problem. Keeping the oil fresh and the oil level correct matters, so check those first.
Toyota
On Toyotas with VVT-i, this often traces to dirty or sludged oil or a sticking oil control valve. Toyotas that went long between oil changes are most prone, so check the oil level and condition first.
Volkswagen
Commonly reported on turbocharged VW and Audi 2.0T engines, where timing chain stretch or a cam adjuster fault can be behind it. Get it checked soon, because a worn chain can cause bigger engine damage.
FAQ
Quick answers
Is it safe to drive with P0012?+
Can I just clear P0012?+
Related codes
Read & clear P0012 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.