P03A5
Cylinder 2 Pressure Too High
What it means
P03A5 means Cylinder 2 Pressure Too High.
Check these first
- A pre-ignition or detonation event on cylinder 2
- Heavy carbon buildup raising compression on cylinder 2
- A failed cylinder 2 pressure sensor reading high
- A mismatched piston or head on cylinder 2
- Over-advanced timing on cylinder 2
What to do next
- Check live cylinder 2 pressure against the other cylinders
- Listen for detonation or ping on cylinder 2
- Compare the cylinder 2 sensor to a known good one
- Check base ignition timing and knock sensor data
- Repair carbon or timing faults if the mechanical test confirms it
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.