What it means
Cylinder-to-cylinder pressure variation on cylinder 2 is below the calibrated minimum — pressure stays unusually constant cycle-to-cycle, often a sign that the closed-loop combustion controller has lost authority or the sensor signal is filtered.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The cylinder 2 pressure sensor tracks combustion pressure from cycle to cycle, and the engine control module uses that variation to assess combustion behavior. This code sets when the reported variation is unusually low, which can indicate a filtered or faulty signal or a combustion control issue.
Common causes
Most likely first.
- Faulty cylinder 2 pressure sensor
- Restricted or filtered sensor signal
- Combustion control fault
- Wiring or connector fault
Symptoms
- Check engine light on
- Rough running or misfire
- Reduced power
- Uneven engine response
How to diagnose it
- Save freeze-frame data and graph cylinder 2 pressure live data across repeated engine cycles to confirm that the unusually low variation is present.
- Compare cylinder 2 data with other cylinders and check for related combustion control or sensor codes.
- Inspect the cylinder 2 sensor connector and harness for corrosion, loose pins, damage, or routing that could interfere with the signal.
- Move the connector and harness gently while watching live data to check for changes that point to an intermittent connection.
- Test the cylinder 2 sensor signal and its circuit, then assess the sensor and combustion control operation against the manufacturer's specification.
Common fixes
- Repair loose, corroded, or damaged cylinder 2 sensor connector terminals.
- Repair wiring damage or routing that is disrupting the cylinder 2 pressure signal.
- Replace the cylinder 2 pressure sensor if its output remains abnormally filtered or unresponsive with a sound circuit.
- Repair a confirmed combustion control fault affecting cylinder 2.
Can I keep driving?
If the engine runs roughly or loses power, limit driving and avoid heavy loads until the cause is identified. A misleading cylinder 2 pressure signal can interfere with combustion control 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.