OBD-II trouble code
P0365: Camshaft Position Sensor 'B' Circuit (Bank 1)
A fault in the second camshaft sensor on Bank 1 — on most dual-overhead-cam engines, the exhaust cam. Losing it rarely stops the engine, but it usually disables exhaust valve timing control.
Quick facts
- System
- Powertrain
- Category
- Camshaft / Timing
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $60 – $500
- DIY difficulty
- Intermediate DIY
What does P0365 mean?
An engine with two camshafts per cylinder head needs to know where both of them are, so it carries two position sensors on that head. The manufacturer designates them 'A' and 'B'. On the overwhelming majority of dual-overhead-cam engines, 'A' is the intake camshaft and 'B' is the exhaust camshaft, and P0365 reports a circuit fault on that second, exhaust-side sensor on Bank 1 — the bank containing cylinder number 1.
Which camshaft it is changes what breaks when the signal goes away. The intake sensor is the one the engine control module (ECM) leans on for injection and spark synchronization, so losing it can produce a hard start or a no-start. The exhaust sensor's main job on most engines is closing the loop on exhaust cam phasing. When it drops out, the ECM cannot verify where the exhaust cam actually is, so it commands the exhaust phaser to its default parked position and leaves it there. The engine keeps running and starts normally, but it runs without exhaust valve timing control.
That produces a specific and fairly recognizable complaint: a rougher idle than usual, a bit less low-end response, and higher emissions — but no drama. Owners often describe the car as feeling flat rather than broken. Because internal exhaust gas recirculation on these engines is achieved by overlapping the cams rather than by a separate EGR valve, parking the exhaust phaser also removes that overlap, which is why an emissions test can fail on a car the driver considers fine.
One consequence worth planning for: on many engines the exhaust cam sensor sits at the rear or the far end of the head, behind the intake plenum or under the cowl, while the intake sensor sits in plain sight at the front. Confirm which one you are actually looking at before you order a part — the two sensors are frequently different part numbers even though they look identical.
Common causes
- Failed Bank 1 'B' (exhaust) camshaft position sensor
- Damaged, chafed or oil-soaked wiring at the exhaust-side sensor connector
- Open or shorted circuit between the sensor and the engine control module
- Oil leaking past the camshaft sensor O-ring and wicking into the connector
- Debris or a damaged tooth on the exhaust camshaft reluctor ring
- Exhaust cam phaser wear that leaves the sensor reading an unstable target
- Poor shared ground affecting both camshaft sensors on the bank
Symptoms
- Check engine light on with P0365 stored
- Rougher idle than normal, particularly when warm
- Noticeably flat or lazy response off idle
- Higher tailpipe emissions and a possible emissions test failure
- Slightly worse fuel economy
- Normal starting, unlike the intake-side camshaft sensor codes
- Possible accompanying exhaust cam timing codes such as P0014 or P0015
Diagnostic steps
- 1.Identify the correct sensor before touching anything. On a dual-cam head the 'B' sensor is normally the exhaust-side one, but confirm against the service information for the specific engine — reversing the two wastes an entire diagnosis.
- 2.Scan for companion codes. Exhaust cam timing codes alongside P0365 suggest the phaser or oil control valve is involved rather than the sensor alone.
- 3.Inspect the sensor connector for oil intrusion. A weeping sensor O-ring feeding oil into the plug is one of the most common causes on this specific sensor.
- 4.Check engine oil level and condition, because the exhaust phaser this sensor monitors is hydraulically actuated and responds badly to low or degraded oil.
- 5.With a scan tool, watch the exhaust camshaft signal and the commanded versus actual exhaust cam position while the engine idles and is revved.
- 6.Test the reference voltage, ground and signal at the sensor connector before condemning the part.
- 7.Remove the sensor and inspect the tip and the reluctor target for debris, scoring or a damaged tooth.
- 8.If the electrical side is sound and cam position still cannot be verified, investigate the exhaust cam oil control valve and its filter screen.
Repair cost
$60 – $500
Sensor parts are typically $40 to $200. Labor varies widely because the exhaust cam sensor is often the less accessible of the two — half an hour on an easy engine, well over two hours on one where the intake plenum or cowl has to come off. If diagnosis leads to the exhaust cam phaser or its oil control valve instead, costs rise substantially and are estimated separately.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with camshaft position sensor replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.