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U0603 Lost Communication With Fuel Pressure Sensor A

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Fuel pressure sensor A reports fuel or rail pressure, which the controller needs for injection quantity and pump control. When the sensor is digital, it transmits over a point-to-point SENT line instead of an analog voltage, and U0603 means its frames no longer arrive in usable form: wire open or shorted, signal stuck high or low, CRC errors or an internal sensor fault. No manufacturer documents this code publicly; Ford's 2023 diesel and 2024 gasoline summaries show the same pattern for other SENT sensors (U0600, U0601) with 5 s to register. CARB 1968.2 demands a dedicated code for lost communication on such inputs. P0190 covers circuit faults of an analog sensor, U0604 the second sensor. Expect a fallback pressure strategy, rough running or no start.

Likely causes

SENT signal, 5 V supply or ground wire faulty
Fuel pressure sensor electronics failed
Loose, corroded or fuel-contaminated connector

Symptoms

  • Check engine light on
  • Reduced power or limp mode
  • Hard start, stalling or no start

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–450
Time0.3–2 h

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

Parts involved

fuel pressure sensor asensor wiring

Related codes

U0604P0190U0600U0601

References: en.wikipedia.org, law.cornell.edu.