P20E0: Exhaust Aftertreatment Fuel Pressure Sensor Circuit High

The doser feed pressure sensor reports a signal above its upper electrical limit. On a typical three-wire sensor this happens when the signal line is open and pulled up, shorted to the 5 V reference or to battery voltage, or when the ground is lost. Volvo and Mack store it as P20E000 and in guide KC-2157 direct technicians to the sensor's wiring and connector. In 2025 both brands also ran service campaigns on 2024–2025 trucks (at Mack with MP7/MP8 engines) built with an AHI fuel pressure sensor outside specification, which could set codes and upset aftertreatment control. Low signal is P20DF, plausibility P20DE and unsteady signal P20E1.

Medium severity. Can I keep driving?Avoid long trips and hard acceleration. If you smell fuel or the car stalls, do not continue.

Symptoms

Check engine light on
Active regeneration blocked

Most likely causes

Signal wire open or shorted to reference or battery voltage
Lost sensor ground
Sensor from a faulty production batch

What to check, in order

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

Check the pump's fuse, relay, and connector
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Replace the filter if it is due for maintenance
Compare commanded and actual pressure in live data
Measure the pressure with a suitable gauge
Check the sensor and regulator before replacing the pump

Good to know

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

What each character of P20E0 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
0: Subsystem depends on the code range
E0: Specific fault in that system

Frequently asked questions

Can I keep driving with code P20E0?

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

What causes code P20E0?

The most common causes are: signal wire open or shorted to reference or battery voltage; lost sensor ground; sensor from a faulty production batch.

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.