Engine oil level too low (listed by RepairPal). Engine oil that doesn't meet the manufacturer's requirements (listed by RepairPal). Camshaft timing control solenoid failed or stuck open, or continuous oil flow to the VCT piston chamber (both sources list the solenoid). Variable valve timing actuator (cam phaser) failure (listed by RepairPal). Incorrect camshaft timing (both sources), or a worn timing chain (listed by RepairPal). Wiring problems in the intake timing control solenoid circuit (listed by OBD-Codes.com).

Top up or change the engine oil and filter with the specified oil. Repair damaged wiring to the timing control solenoid. Clean or replace a sticking camshaft timing (oil control) solenoid. Replace the variable valve timing actuator (cam phaser). Replace a worn timing chain and correct camshaft timing.

P0012🔧 Engine timing / variable valve timingStop and fix promptly

P0012: "A" Camshaft Timing Over-Retarded (Bank 1) (Meaning, Causes, Fixes)

Q: What does P0012 mean?

P0012 means the engine computer found the Bank 1 'A' camshaft (usually the intake cam) more retarded than it should be, or not responding to the variable valve timing position it requested. Common causes are low or wrong engine oil, a sticking or stuck-open timing control (oil control) solenoid, a failed cam phaser, incorrect cam timing or a worn timing chain. Many modern engines use variable valve timing (VVT, also called VCT) to shift the camshaft relative to the crankshaft for more power or better efficiency at different engine speeds. The engine computer (PCM/ECM) does this with an oil control solenoid that sends engine oil pressure to a camshaft actuator (phaser). OBD-Codes.com says P0012 is set when the cam timing is over-retarded, and RepairPal says the PCM sets it when the camshaft does not respond as the PCM requests. The 'A' camshaft is the intake, left or front camshaft, and Bank 1 is the side of the engine with cylinder 1. P0011 is the over-advanced version of the same check, and P0015 is the over-retarded check for camshaft 'B' (usually exhaust). It is a generic OBD-II code seen on Toyota, VW, Honda, Chevrolet, Hyundai, Audi, Acura and others (OBD-Codes.com). The sources put the emphasis in different places: OBD-Codes.com says the main thing to check is a sticking VCT solenoid valve caused by contamination, while RepairPal leads with engine oil level and oil specification and lists an oil and filter change as its common repair.

Q: Can I keep driving with P0012?

Stop and fix promptly. Get this diagnosed promptly. RepairPal rates P0012 'Urgent', meaning it can cause severe damage or be unsafe. OBD-Codes.com lists hard starting, poor idle and stalling as likely symptoms, and a stall in traffic is a real hazard. Check your oil level right away, since low oil is one of the causes RepairPal lists, and avoid driving if the engine stalls, knocks or runs badly.

Reviewed 2026-10-22 · Based on 2 cited source(s)

What P0012 means

Many modern engines use variable valve timing (VVT, also called VCT) to shift the camshaft relative to the crankshaft for more power or better efficiency at different engine speeds. The engine computer (PCM/ECM) does this with an oil control solenoid that sends engine oil pressure to a camshaft actuator (phaser). OBD-Codes.com says P0012 is set when the cam timing is over-retarded, and RepairPal says the PCM sets it when the camshaft does not respond as the PCM requests. The 'A' camshaft is the intake, left or front camshaft, and Bank 1 is the side of the engine with cylinder 1. P0011 is the over-advanced version of the same check, and P0015 is the over-retarded check for camshaft 'B' (usually exhaust). It is a generic OBD-II code seen on Toyota, VW, Honda, Chevrolet, Hyundai, Audi, Acura and others (OBD-Codes.com). The sources put the emphasis in different places: OBD-Codes.com says the main thing to check is a sticking VCT solenoid valve caused by contamination, while RepairPal leads with engine oil level and oil specification and lists an oil and filter change as its common repair.

Severity: can I keep driving?

Stop and fix promptly

Get this diagnosed promptly. RepairPal rates P0012 'Urgent', meaning it can cause severe damage or be unsafe. OBD-Codes.com lists hard starting, poor idle and stalling as likely symptoms, and a stall in traffic is a real hazard. Check your oil level right away, since low oil is one of the causes RepairPal lists, and avoid driving if the engine stalls, knocks or runs badly.

Common symptoms

Check engine light on
Hard starting (listed by OBD-Codes.com)
Poor or rough idle (listed by OBD-Codes.com)
Stalling (listed by OBD-Codes.com)
Decreased engine performance (listed by RepairPal)
Increased fuel consumption (listed by RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Engine oil level too low (listed by RepairPal)
Engine oil that doesn't meet the manufacturer's requirements (listed by RepairPal)
Camshaft timing control solenoid failed or stuck open, or continuous oil flow to the VCT piston chamber (both sources list the solenoid)
Variable valve timing actuator (cam phaser) failure (listed by RepairPal)
Incorrect camshaft timing (both sources), or a worn timing chain (listed by RepairPal)
Wiring problems in the intake timing control solenoid circuit (listed by OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Check the engine oil level and condition first, and confirm the oil viscosity matches your owner's manual. RepairPal lists low or incorrect oil as causes and an oil and filter change as the common repair.
Read all stored codes. P0011, P0014, P0015, P0016 or P0021 alongside P0012 help narrow it down to a camshaft, a bank, or timing chain correlation.
Inspect the wiring and connector at the intake camshaft timing control solenoid for damage or oil contamination.
After correcting the oil, clear the code and drive normally to see if it returns.

Typical fixes

Top up or change the engine oil and filter with the specified oil
Repair damaged wiring to the timing control solenoid
Clean or replace a sticking camshaft timing (oil control) solenoid
Replace the variable valve timing actuator (cam phaser)
Replace a worn timing chain and correct camshaft timing

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Testing the VCT unit follows vehicle-specific procedures, and dealer techs can command and test components with a scan tool (OBD-Codes.com)
The code comes back after an oil change with the correct oil
The engine stalls, knocks or rattles
P0016/P0017 correlation codes also appear, pointing to possible timing chain wear

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can an oil change fix P0012?

Sometimes. RepairPal lists low oil and oil that doesn't meet the manufacturer's requirements as causes, and an oil and filter change as the common repair, because the timing system is driven by oil pressure. If the code returns, the solenoid, phaser, cam timing or timing chain need checking.

What's the difference between P0011 and P0012?

Both are Bank 1 camshaft 'A' (usually intake) timing codes. P0011 means the timing is over-advanced or not performing as expected, and P0012 means it is over-retarded.

Is it safe to drive with P0012?

RepairPal rates it 'Urgent'. Since OBD-Codes.com lists stalling as a possible symptom, get it diagnosed soon and don't drive if the engine stalls or runs badly.

How much does it cost to fix P0012?

Neither source gives a repair cost. It can range from an oil and filter change to a solenoid, cam phaser or timing chain job, so get a diagnosis and a written estimate first.

Sources

Last reviewed 2026-10-22. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.