On some engines the exhaust cam phaser (camshaft position actuator B) has its own position sensors, which tell the engine module where the phaser actually is; sensor C is the third of them, bank 1 the side with cylinder 1. This is a different family from the sliding-cam position sensors (P2C05 ff). P03F7 means the signal is electrically valid but implausible – it does not match the commanded phaser position or the camshaft and crankshaft sensors, jumps, or lies outside the adjustment range. No manufacturer document available to us uses this code (GM, Ford and FCA tables checked); the intake counterpart P03E5 ff is equally unused. The phaser is then usually held in its base position.
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
- Exhaust cam phasing held in its base position, loss of power
- Possibly rough idle or poorer emissions
Most likely causes
- Sensor signal implausible (drift, loose target or magnet)
- Phaser stiff, actual position deviates
- Loose contact or interference
- Valve timing wrong after a repair
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It can trigger limp mode.
- It affects emissions.
What each character of P03F7 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 3: Ignition and misfires
- F7: Specific fault in that system
Frequently asked questions
Can I keep driving with code P03F7?
Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
What causes code P03F7?
The most common causes are: sensor signal implausible (drift, loose target or magnet); phaser stiff, actual position deviates; loose contact or interference.
Related codes
- P03F6B Camshaft Position Actuator Position Sensor C Circuit Bank 1
- P03F8B Camshaft Position Actuator Position Sensor C Circuit Low Bank 1
- P03F9B Camshaft Position Actuator Position Sensor C Circuit High Bank 1
- P03E6A Camshaft Position Actuator Position Sensor C Range/Performance Bank 1
- P2B48B Camshaft Position Actuator Position Sensor B Range/Performance Bank 1
- P0014"B" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
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.