P0365 — Camshaft Position Sensor B Circuit (Bank 1)
P0365 means the ECM detected a fault in the camshaft position sensor B circuit on bank 1, usually the second cam sensor on that bank (often the exhaust camshaft on dual-overhead-cam gas engines). Which camshaft sensor B refers to differs by engine, so check the OEM definition.
What this means for truckers
P0365 (Camshaft Position Sensor B Circuit, Bank 1) — secondary cam sensor on some HD diesels (Cummins X15 has dual cam sensors). Same diagnostic as P0340/P0344.
Before you replace parts — try this first
P0365 on the Ignition system is most often failed camshaft position sensor b — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Check-engine light, possibly longer cranking, rough idle and reduced power. On gas engines with variable exhaust cam timing, that function may be disabled. Many engines still start and run.
Common causes
- CommonFailed camshaft position sensor B ($120–$450)
- CommonDamaged wiring or connector at sensor B ($100–$450)
- OccasionalOpen or shorted 5-volt reference or ground ($100–$600)
- RareDamaged target wheel or incorrect cam timing ($300–$3000)
How to fix
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → P0300 — Random/Multiple Cylinder Misfire Detected
- → P0301 — Cylinder 1 Misfire Detected
- → P0302 — Cylinder 2 Misfire Detected
- → P0303 — Cylinder 3 Misfire Detected
- → P0304 — Cylinder 4 Misfire Detected