P0368
PowertrainCamshaft Position Sensor "B" Circuit High Input (Bank 1)
The ECU is seeing too much voltage coming back from the 'B' camshaft position sensor on bank 1, which usually points at a wiring or connector problem rather than the engine itself going wrong. The cam sensor tells the ECU exactly where the camshaft is so it can time the spark and injection correctly, so when that signal goes haywire the engine can run rough or refuse to start cleanly. For most owners this shows up as a warning light and an engine that feels a bit unsettled, and the fix is often cheaper than the symptoms suggest once you trace the cause.
ⓘ Information only. This page provides general educational information about fault code P0368. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0368 mean?
P0368 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Camshaft Position Sensor "B" Circuit High Input (Bank 1).
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on the dash, sometimes the first and only sign
- • Lumpy or uneven idle, worst when the engine is cold or sitting at a junction
- • Hesitation or a flat spot when you put your foot down
- • Long cranking before it fires, and on a bad day it won't start at all
- • Stalling at idle or when the engine is under load
- • General lack of pull and a sluggish feel through the rev range
Possible causes
Causes commonly associated with P0368, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Damaged, chafed or corroded wiring at the cam sensor connector, the usual culprit and the first thing to rule out
- 2. A short in the signal wire pulling it up to the 5V reference or battery voltage, which is exactly what 'high input' means
- 3. Oil contamination in the connector, common on engines where the cam cover or sensor seal weeps and oil tracks down the loom
- 4. The cam sensor 'B' itself failing internally, which does happen but less often than the wiring
- 5. Spread, dirty or loose pins at the sensor or the ECU plug giving a poor connection
- 6. A failed crank sensor on some vehicles, where the ECU stores cam codes because the two signals don't agree
- 7. ECU input-stage damage, rare and worth chasing only after everything else checks out clean
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Read the codes and note anything sitting alongside it, particularly other cam or crank faults like P0365, P0366, P0016 or P0017, because those change the picture
- 2. Get your eyes on the cam sensor connector and the loom feeding it on bank 1, looking for chafing, green corrosion, melted insulation or oil that's wicked into the plug
- 3. Check around the sensor for an oil or coolant weep, since fluid getting into the connector is a classic cause of a high-input reading
- 4. Back-probe the signal wire with a multimeter at idle, you want it swinging within roughly 0.5 to 4.5V; a reading pinned above 4.5V confirms the circuit is sitting high
- 5. Unplug the sensor and check the signal wire to ground for continuity, infinite resistance means an open and near-zero means it's shorted somewhere
- 6. If the loom and sensor both test fine, that's when you bring in someone with a scope or look harder at the ECU input, not before
Common questions about P0368
Is this the sensor gone bad, or is it the wiring and plug? +
On a P0368 the wiring and connector are the prime suspect more than the sensor element, because 'high input' is the ECU reading too much voltage and that's exactly what a short or a corroded plug produces. Oil tracking down the loom into the connector is a very common cause, so clean and inspect the plug first. The sensor itself can fail internally, but don't condemn a perfectly good £40 part before you've checked the £0 wiring. Back-probe the signal wire and you'll know which way to go.
How long does this usually take to put right? +
A connector clean-up or a repair to a chafed bit of loom is often an hour or less once you've found it. Swapping the cam sensor is typically a 30 to 60 minute job on most engines, longer if it's buried behind the inlet manifold or other bits have to come off to reach it. The diagnosis is where the time actually goes, so a garage charging for half an hour to an hour of fault-finding before they touch anything is being honest with you.
Is a cheap aftermarket cam sensor worth fitting? +
A decent branded aftermarket sensor from the likes of Bosch, Hella or Delphi is fine and a fraction of dealer money. Where people come unstuck is the cheapest no-name parts off eBay, which can read slightly off and either fail again or set the code straight back. Spend a bit more for a reputable brand, fit the connector clip properly, and it'll be as good as the original. Skip the bargain-basement stuff.
Can I keep driving with this showing? +
You can usually limp it home, but I wouldn't make a habit of it. A flaky cam signal can drop the engine into limp mode, stall you at a roundabout or leave you cranking on a cold morning, none of which you want in traffic. Long term a bad timing signal can throw in misfires and put unburnt fuel through the cat, which turns a cheap fix into an expensive one. Sort it sooner rather than later.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →