What it means
Cylinder 3 pressure sensor reads in range but plausibility check fails. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The cylinder 3 pressure sensor measures combustion pressure for the engine control module. This code sets when the sensor signal is present but does not match the expected range or behavior for cylinder 3, suggesting sensor drift, mounting effects, or a circuit problem.
Common causes
Most likely first.
- Sensor drift
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check engine light on
- Rough running or misfire
- Reduced engine power
- Hard starting
How to diagnose it
- Save freeze-frame data and compare cylinder 3 pressure live data with the other cylinders under similar operating conditions.
- Inspect the cylinder 3 sensor connector and harness for corrosion, chafing, loose pins, or signs of water entry.
- Check that the cylinder 3 sensor is securely mounted and that its installation does not appear loose or damaged.
- With live data displayed, gently move the connector and harness to see whether cylinder 3 readings change unexpectedly.
- Test the sensor signal and circuit against the manufacturer's specification to distinguish sensor drift from a wiring fault.
Common fixes
- Repair damaged or poorly seated cylinder 3 sensor connector terminals.
- Repair chafed or loose cylinder 3 sensor wiring.
- Correct a confirmed loose or faulty sensor mounting.
- Replace the cylinder 3 pressure sensor if its signal remains outside the expected range with a sound circuit.
Can I keep driving?
If the engine runs roughly, starts hard, or loses power, keep driving to a minimum and avoid heavy loads until the fault is diagnosed. An unreliable cylinder 3 pressure reading can impair combustion monitoring and increase emissions.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.