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U068A Lost Communication With Barometric Pressure Sensor C

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Barometric sensor C appears in two very different layouts. In GM's dual-throttle tables 23OBDG07/24OBDG07 it measures the air ahead of the bank 1 throttle; P227C and P227D judge its raw value (under 50 or over 115 kPa, 2 s), and U068A is set once the bank 1 SENT frames carry an incorrect length for 1.5 s, two trips to MIL. Oddly, GM's description calls the part pressure sensor 2 although the frames are labelled bank 1. GM's diesel tables 25OBDG04A/04B place sensor C inside a LIN air-mass meter instead: a low reading there sets P227C (Type B), but a missing reply is logged as U060F for the meter, not as U068A. U0680 is the bank 2 partner. The controller falls back on modelled pressure.

Likely causes

Signal, supply or ground wire to sensor C damaged
Connector at the intake pressure sensor loose or corroded
Sensor C electronics failed
Engine controller software fault

Symptoms

  • Check engine light after two trips
  • Bank 1 fueling less precise
  • Accompanying pressure codes P227B to P227D possible

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–400
Time0.3–2 h

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

Parts involved

baro sensor cvehicle bus wiring

Related codes

U0680U067FU060FP227AP227BP227CP227DP227E

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, law.cornell.edu.