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P0365 to P0369: camshaft position sensor B circuit
Sensor B is usually the exhaust camshaft. On a twin-cam engine with variable timing on both shafts, that sensor is doing real work — not sitting there as a spare.
An engine with variable timing on both camshafts needs to know where both of them are. Sensor A watches one; sensor B watches the other.
| Code | Meaning |
|---|---|
| P0365 | Camshaft position sensor B circuit, bank 1 |
| P0366 | Range/performance |
| P0367 | Circuit low |
| P0368 | Circuit high |
| P0369 | Circuit intermittent |
The bank 2 equivalents run from P0390.
Related: P0340 camshaft position sensor and P0341 and P0344.
Which camshaft is B?
Convention on most engines: A is intake, B is exhaust. But it is convention rather than law, and some manufacturers reverse it.
Check the specification for your engine before removing anything. On a transverse engine with poor access, removing the wrong sensor is a genuine waste of an hour.
Why exhaust cam timing matters
On engines with variable timing on the exhaust side, the exhaust cam controls internal exhaust gas recirculation — holding the exhaust valve open slightly into the intake stroke, so some exhaust gas stays in the cylinder.
This lowers combustion temperature and reduces NOx, and on many modern engines it partly or entirely replaces an external EGR valve.
The consequence: a stuck exhaust phaser produces emissions and driveability symptoms that look like an EGR fault. If you have exhaust cam codes and are chasing an EGR problem, they may be the same problem.
P0404 EGR position sensor diagnostics.
Causes
Same list as sensor A, with the same order.
Oil in the connector
These sensors thread into the cylinder head, and camshaft seals leak. Oil enters the connector and wicks along the wiring.
Fix the leak, not just the connector. Cleaning without addressing the source means the fault returns within months.
The connector and wiring
Latch condition, pin tension, chafing at brackets. Standard, and worth doing before buying parts.
The sensor
Hall or inductive depending on the engine. Both fail with age and heat, and both fail intermittently before failing completely.
The reluctor on the camshaft
A trigger wheel or a machined feature on the cam. Damage is rare but produces range/performance codes rather than circuit codes.
Actual cam timing being wrong
If the exhaust phaser is stuck or the chain has stretched, the sensor reports a real deviation. That is a mechanical fault, not a sensor fault: P0010 and P0013 camshaft actuator circuit.
The data to log
Commanded versus actual exhaust camshaft position.
| Behaviour | Meaning |
|---|---|
| Actual follows commanded | System healthy |
| Actual never moves | Stuck phaser or blocked oil control valve |
| Actual moves slowly | Restricted oil flow — check the solenoid screen |
| No actual value at all | Sensor or circuit fault |
If actual position is missing entirely rather than wrong, the sensor is the problem. If it is present and stubborn, look at the oil control valve and the oil itself.
Symptoms
- Rough idle, worse when cold.
- A flat spot in the mid range.
- Slightly increased fuel consumption.
- Emissions test failure on NOx, if the engine relies on internal EGR.
- Occasionally no symptom at all.
That last case is common enough to be worth stating. Many drivers meet these codes only through the warning lamp.
The oil connection again
Every variable valve timing fault traces back to oil eventually. Wrong viscosity, extended intervals, low level, or sludge from short-trip driving.
Before condemning hardware on any VVT code, ask when the oil was last changed and to what specification: engine oil viscosity and approvals.
An oil and filter change with the correct specification is a legitimate first step on an engine with unknown history, not a stalling tactic.
In what order
- Identify which camshaft is B for your engine.
- Read all codes — a bank 2 or sensor A code alongside changes the picture.
- Inspect the connector for oil.
- Log commanded versus actual cam position.
- Check the oil control valve screen if actual lags or does not move.
- Replace the sensor only if no actual value appears at all.
- Address the oil leak if there was one.
Log both camshaft positions against their commanded values — an ELM327 adapter and the free tier of the app are all it takes. Seeing which shaft responds and which does not takes the guesswork out entirely.
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