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U068C Lost Communication With Turbocharger/Supercharger Inlet Pressure Sensor B

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

A second inlet pressure sensor makes sense where each bank breathes through its own filter and charger, or where a two-stage system needs the pressure ahead of the second compressor. U068C means the digital frames from that sensor B no longer arrive in usable form. No manufacturer documents U068C publicly; Ford's 2023 diesel summary, the only examined table with an inlet pressure U code, runs just sensor A over SENT (U068B), and no GM table lists either code. Faults of an analog sensor B are P2374 to P2378. CARB lists compressor inlet pressure among the required diesel data. The controller then models the pressure on that side, so filter restriction there goes unseen and boost targets get more cautious.

Likely causes

Signal, supply or ground wire to inlet sensor B damaged
Connector loose or contaminated with oil
Sensor B electronics failed

Symptoms

  • Check engine light
  • Filter restriction on that side no longer detected
  • Slightly lower boost possible

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 bvehicle bus wiring

Related codes

U068BP2374P2375P2376P2377P2378

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