OBD-II trouble code
P0368: Camshaft Position Sensor 'B' Circuit High (Bank 1)
Signal voltage on the Bank 1 exhaust camshaft sensor is stuck at the top of its range, meaning an open circuit. Water intrusion is a disproportionate cause here, because of where this particular sensor tends to live.
Quick facts
- System
- Powertrain
- Category
- Camshaft / Timing
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $40 – $450
- DIY difficulty
- Intermediate DIY
What does P0368 mean?
The engine control module (ECM) holds the camshaft sensor signal line at a reference level and expects the sensor to pull it down repeatedly as the reluctor teeth pass. P0368 means that line on the Bank 1 'B' — normally the exhaust — camshaft sensor is staying up where the module put it. Nothing is pulling it down, so the circuit is effectively open somewhere between the module and whatever should be switching it.
What gives this code its own character is location. On a great many transverse and inline dual-cam engines, the intake camshaft sensor sits at the accessible front of the head while the exhaust camshaft sensor sits at the back, under or near the cowl. That is the lowest point of the water channel that runs across the base of the windshield, and when a cowl drain clogs with leaf litter, water sits exactly where the exhaust cam sensor connector is. It does not have to flood; repeated wet-dry cycles are enough to grow green corrosion on the terminals, and corrosion raises resistance until the module reads the circuit as open.
That pattern is worth checking before condemning parts, because it explains two things people find confusing. It explains why P0368 shows up disproportionately in autumn and after heavy rain rather than uniformly through the year, and it explains why replacing the sensor sometimes fixes it for a season and then it returns — the new sensor was installed into the same corroded connector, sitting under the same blocked drain.
An open circuit here does not usually stop the engine. Exhaust cam phasing gets parked at its default position, the idle roughens slightly and the engine feels less responsive down low, but it starts and drives. That mildness is precisely why the corrosion often gets months to progress before anyone investigates.
Common causes
- Corroded terminals in the exhaust camshaft sensor connector from cowl water intrusion
- Open or broken signal wire between the sensor and the engine control module
- Open sensor ground circuit, leaving the sensor unable to pull the line down
- Failed sensor that no longer switches its output
- Terminal backed out of the connector body and no longer making contact
- Connector left unseated after work on the rear of the cylinder head
- Reluctor ring on the exhaust camshaft damaged or spun, so nothing triggers the sensor
Symptoms
- Check engine light on with P0368 stored
- Slightly rough idle, more noticeable when the engine is warm
- Flat or unresponsive feel at low engine speeds
- Reduced fuel economy
- Higher emissions and a likely emissions inspection failure
- Symptoms that first appeared after heavy rain or a car wash
- Engine starts and runs normally otherwise
Diagnostic steps
- 1.Locate the sensor before testing. If the exhaust cam sensor sits at the rear of the head near the cowl, inspect that area for standing water, leaf debris, and blocked cowl drains.
- 2.Unplug the connector and examine the terminals under good light for green or white corrosion, which raises resistance enough to look like an open circuit to the module.
- 3.Measure voltage drop on the sensor ground with the key on rather than checking continuity alone — corroded terminals frequently pass a continuity test and still fail under load.
- 4.Confirm reference voltage is present at the harness connector. Reference present, ground good, and the line still stuck high points at the sensor itself.
- 5.Back-probe the signal wire and crank while watching for any toggle. A flat line at reference with a known-good sensor means the open is upstream in the harness.
- 6.If corrosion is found, clean or replace the terminals rather than only the sensor, and address the water source. A new sensor in a corroded plug fails again.
- 7.Remove the sensor and inspect the exhaust camshaft reluctor target for damage before ordering parts.
- 8.After repair, verify the signal switches on live data and that exhaust cam phasing follows command.
Repair cost
$40 – $450
Cleaning a corroded connector and clearing a blocked cowl drain can be a $40 to $150 job. A sensor replacement is typically $40 to $200 in parts plus half an hour to two hours of labor, with the higher end applying when the sensor is behind the cowl or the intake plenum. Terminal repair or a harness splice usually adds $80 to $220.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with wiring harness / circuit repair 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.