What P0366 means
Camshaft position sensor B is the exhaust camshaft sensor (bank 1 = side with cylinder 1), usually a Hall sensor on the exhaust cam phaser.
How the engine computer detects it
P0366 means its pulses arrive, but their number or position does not fit the crankshaft. GM expects 400 pulses per 100 engine cycles and sets the code outside 398–402, or with fewer than 4 or more than 6 pulses in the first 12 reference events at start, 8 of 10 samples, after two trips. On GM's 3.6-liter V6 in the Saab 9-4X the exhaust phaser then goes to its park position and ignition runs from the crankshaft alone; on the 2.8 turbo V6 (LAU) the fault must last 1 s, or 10 s cumulatively, below 2,520 rpm. Saab's workshop information names a damaged tone wheel, play, foreign matter and too large an air gap. Ford uses the code too but publishes no thresholds.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Longer cranking before the engine starts
- Loss of power or rough idle (exhaust cam timing in its base position)
- Higher fuel consumption
Common causes
- Sensor faulty or dirty (metal debris on the magnet) Most likely
- Wiring close to ignition coils or solenoids, loose contact Possible
- Tone wheel on the phaser damaged or loose, air gap too large Possible
- Sensor or phaser wrongly fitted after timing drive work Less likely
How to diagnose P0366
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: camshaft position sensor exhaust, camshaft tone wheel, sensor wiring, engine control module, cam phaser exhaust bank1.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 3
- Ignition system or misfire
- 66
- Specific fault
Questions drivers ask
Can I drive with code P0366?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0366?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0366 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0366 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: easy. Start with the cheapest checks before replacing expensive parts.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0366. They can point to a shared cause, so it's worth checking them together.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.