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U068B Lost Communication With Turbocharger/Supercharger Inlet Pressure Sensor A

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

The inlet pressure sensor sits between air filter and compressor. Its reading shows filter restriction and, together with boost pressure, the pressure ratio the compressor works against. Ford's 2023 diesel summary connects sensor A via SENT and lists U068B in its SENT sensor group: U068B follows when the low-level SENT driver sees the signal line pinned to one voltage level, either up or down, monitored without pause and judged over 5 s. A sensor that still talks but raises its own error flag or reports data above a threshold sets P012A instead. Combined pressure and temperature chips such as Infineon's KP276 deliver this kind of SENT signal. U068C is the code for a second inlet sensor. Without the value the controller estimates inlet pressure, and boost or filter monitoring become less precise.

Likely causes

SENT signal wire shorted to ground or voltage, or open
Connector on the intake duct loose, oily or corroded
Inlet pressure sensor failed

Symptoms

  • Check engine light
  • Air filter restriction no longer monitored
  • Possibly somewhat reduced boost

Repair estimate

DifficultyEasyDIY possible
Parts and labour€50–350
Time0.3–1.5 h

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

Parts involved

turbo inlet pressure sensor avehicle bus wiring

Related codes

U068CP012AP012BP012CP012DP012E

References: fordservicecontent.com, infineon.com, law.cornell.edu.