Powertrain, generic (extended)

P20E1 Exhaust Aftertreatment Fuel Pressure Sensor Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The signal from the pressure sensor in the doser feed line jumps or drops out for short moments, faster than real line pressure could change. Usual reasons are a loose pin, a cracked wire flexing with engine movement, or moisture in the connector. No manufacturer documents P20E1 publicly. Comparable sensors exist on Volvo and Mack AHI modules, where a faulty sensor batch led to a 2025 service campaign, and on the Detroit hydrocarbon doser block, whose fuel compensation pressure sensor became a separate service part. CARB requires circuit checks for every sensor of an in-exhaust injection system. Steady faults belong to P20DD, P20DF and P20E0.

Likely causes

Loose or fretted pins at the sensor connector
Wire breaking intermittently from vibration
Internal fault in the pressure sensor

Symptoms

  • Check engine light on, possibly coming and going
  • Regenerations interrupted

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–600
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

aftertreatment fuel pressure sensor

Related codes

P20DDP20DEP20DFP20E0

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.