What are the common causes of P236B?

Low compression in cylinder 12 from worn rings or valves. A failed cylinder 12 pressure sensor reading low. A leak past the cylinder 12 pressure sensor seal. A faulty cylinder 12 fuel injector cutting cylinder pressure.

Read cylinder 12 pressure on a scan tool. Perform a compression test on cylinder 12. Inspect the cylinder 12 pressure sensor seal for leaks. Test the cylinder 12 fuel injector. Replace the cylinder 12 pressure sensor if the mechanical checks pass. Clear the code and retest.

P236B

Cylinder 12 Pressure Too Low

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

What it means

P236B means Cylinder 12 Pressure Too Low.

Check these first

Low compression in cylinder 12 from worn rings or valves
A failed cylinder 12 pressure sensor reading low
A leak past the cylinder 12 pressure sensor seal
A faulty cylinder 12 fuel injector cutting cylinder pressure

What to do next

Read cylinder 12 pressure on a scan tool
Perform a compression test on cylinder 12
Inspect the cylinder 12 pressure sensor seal for leaks
Test the cylinder 12 fuel injector
Replace the cylinder 12 pressure sensor if the mechanical checks pass
Clear the code and retest

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Updated

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