P01C5: Fuel Pressure Sensor A Circuit Low

Fuel pressure sensor A is a fuel pressure sensor without 'rail' in its name and without a bank – unlike the rail pressure sensors P0190–P0194 and P01BE–P01C2; which sensor it is depends on the manufacturer. The only documented case is FCA, where sensor A is the low-pressure sensor in the supply line, read together with the fuel pump control module. GM calls its low-pressure sensor 'sensor B' (P018A–P018E). P01C5 means the signal voltage is below its lower limit – typically a signal wire shorted to ground or an open signal or 5 V reference wire (GM's comparable limit is 4 % of the reference). No manufacturer document using exactly this code was found; the description rests on CARB's circuit monitoring requirement, the FCA sibling code P01C6 and GM's equivalent low-pressure sensor checks.

Symptoms

• Check engine light on
• Hard starting or stalling possible
• Hesitation or lack of power under load

Most likely causes

• Signal wire shorted to ground or open
• 5 V reference missing
• Connector corroded or wet
• Sensor faulty

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the pump's fuse, relay, and connector
2. With the connector unplugged, check whether the signal wire is making contact with ground.
3. Replace the filter if it is due for maintenance
4. Compare commanded and actual pressure in live data
5. Measure the pressure with a suitable gauge
6. Check the sensor and regulator before replacing the pump

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P01C5 means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 1: Air and fuel
• C5: Specific fault in that system

Frequently asked questions

Can I keep driving with code P01C5?

Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

What causes code P01C5?

The most common causes are: signal wire shorted to ground or open; 5 V reference missing; connector corroded or wet.

Related codes

• P01C3Fuel Pressure Sensor A Circuit
• P01C4Fuel Pressure Sensor A Circuit Range/Performance
• P01C6Fuel Pressure Sensor A Circuit High
• P01C7Fuel Pressure Sensor A Circuit Intermittent/Erratic
• P018CFuel Pressure Sensor B Circuit Low

Sources

• law.cornell.edu: 13 CCR 1968.2
• static.nhtsa.gov: MC 10227984 9999
• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.