OBD Codes List

Diagnostic reference · P234B

P234B

Cylinder 9 Pressure Sensor Circuit High

System
Ignition and misfire (P code)
Lamp
Check Engine Light
Category
Powertrain - Ignition

What it means

P234B means Cylinder 9 Pressure Sensor Circuit High.

Where it lives

For P234B, the sensor sits on the circuit this code reports. The description of P234B puts it on cylinder 9.

Check these first

  • A short to voltage on the cylinder 9 pressure sensor signal wire
  • An open in the cylinder 9 sensor ground circuit
  • A failed cylinder 9 pressure sensor
  • Water or corrosion in the cylinder 9 sensor connector

What to do next

  1. Read cylinder 9 pressure sensor voltage on a scan tool
  2. Test the cylinder 9 sensor signal wire for a short to voltage
  3. Check the cylinder 9 sensor ground circuit and connector
  4. Replace the cylinder 9 pressure sensor if the circuit tests good
  5. Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.