What it means
Cylinder 2 pressure sensor below lower plausibility — short to ground. 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 2 pressure sensor sends a combustion-pressure signal to the engine control module, which checks that the signal is plausible. This code sets when the signal falls below the expected range, commonly because it is shorted to ground or the circuit has a poor connection.
Common causes
Most likely first.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check engine light on
- Rough running or misfire
- Reduced engine power
- Hard starting
How to diagnose it
- Use a scan tool to save freeze-frame data and confirm whether the cylinder 2 pressure reading is low when the fault is active.
- Inspect the cylinder 2 sensor connector for corrosion, moisture, loose pins, or a terminal pushed out of position.
- Check the cylinder 2 harness for chafing or worn insulation that could let the signal wire contact ground.
- With the wiring diagram, test the cylinder 2 signal circuit for a short to ground and check its power and ground connections.
- If the circuit is sound, compare the cylinder 2 sensor output with the manufacturer's specification.
Common fixes
- Clean and secure the cylinder 2 sensor connector if its contacts are intact.
- Repair the cylinder 2 signal wire where it is shorted to ground or chafed.
- Replace damaged cylinder 2 connector terminals or harness sections.
- Replace the cylinder 2 pressure sensor if it fails output checks with a sound circuit.
Can I keep driving?
If the engine runs roughly or loses power, keep driving to a minimum and avoid heavy loads; stop if it misfires severely or stalls. An unreliable cylinder 2 pressure signal can disrupt 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.