P2539: Low Pressure Fuel System Sensor Circuit

P2539 is the general circuit code of the sensor that reports the supply pressure ahead of the high-pressure pump. In VW's 2014 specification books for the Passat, CC and Touareg it is set once the signal exceeds 4.80 V, which the Passat book attributes to a broken line or contact with the positive supply; below 0.2 V VW stores P2541 instead. Deutz's EMR controller files P2539-F0 for a ground fault of the supply pressure sensor. Ford's 2015 Transit with the 3.2 L Duratorq TDCi has a pressure switch: per SSM 51033, units built from 6 March 2015 may log P2539 in a key-on engine-off self-test because no switch change is seen after shutdown, and the code can be ignored if the engine-running test and the MIL are clean. P2540 to P2543 narrow the fault down. Without the signal, supply pressure control runs on a substitute value.

Medium severity. Can I keep driving?You can drive in moderation for a short time. A very lean or very rich mixture can damage the engine or the catalytic converter.

Symptoms

Check engine light
Hesitation or reduced power under load
Hard starting, especially after standing

Most likely causes

Signal or ground wire open, connector not engaged
Signal wire shorted to the 5 V reference or battery voltage
Failed low-pressure fuel sensor or pressure switch
Code logged only in a static self-test without a real fault (Ford Transit 2015)

What to check, in order

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

Check short-term and long-term fuel trims in live data
With the connector unplugged, check whether the signal wire is making contact with ground.
Look for air leaks at hoses and gaskets
Check the mass air flow sensor (MAF) and, if appropriate, clean it with a dedicated cleaner
Measure the fuel pressure
Check the injectors and the oxygen sensor

Good to know

Repair difficulty: medium
It can trigger limp mode.
It affects emissions.

What each character of P2539 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
5: Speed and idle
39: Specific fault in that system

Frequently asked questions

Can I keep driving with code P2539?

You can drive in moderation for a short time. A very lean or very rich mixture can damage the engine or the catalytic converter.

What causes code P2539?

The most common causes are: signal or ground wire open, connector not engaged; signal wire shorted to the 5 V reference or battery voltage; failed low-pressure fuel sensor or pressure switch.

Related codes

Sources

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.