What are the common causes of P009C?

A short to ground in the fuel pressure relief control circuit. A failed fuel pressure relief valve. A failed fuel pressure sensor. Low voltage at the fuel pressure relief control.

Read the code and note the fuel pressure relief fault. Test the fuel pressure relief control circuit for a short to ground. Inspect the relief valve connector for corrosion. Command the fuel pressure relief valve and watch pressure in live data. Replace the fuel pressure relief valve if it does not respond. Clear the code and retest.

P009C

Fuel Pressure Relief Control Circuit Low

System: Fuel and air metering (P code)
Lamp: Check Engine Light
Category: Powertrain - Fuel/Air Metering

What it means

P009C means Fuel Pressure Relief Control Circuit Low.

Check these first

A short to ground in the fuel pressure relief control circuit
A failed fuel pressure relief valve
A failed fuel pressure sensor
Low voltage at the fuel pressure relief control

What to do next

Read the code and note the fuel pressure relief fault
Test the fuel pressure relief control circuit for a short to ground
Inspect the relief valve connector for corrosion
Command the fuel pressure relief valve and watch pressure in live data
Replace the fuel pressure relief valve if it does not respond
Clear the code and retest

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Updated

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