Powertrain, generic (extended)

P2C0A A Camshaft Profile Actuator Position Sensor B Range/Performance Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Here the wiring of position sensor B is intact, but its report does not match what the second intake actuator on bank 1 was told to do. On the L3B, GM follows every shift through three Hall readings: below 55 while the pin is moving out, below 45 once fully out, and above 68 when it is back home. P2C0A is stored if this sequence is not seen after a command, or if the feedback shows pin activity although the ECM never asked for a shift. Four bad readings in five, engine running, more than 11 V and no crank or cam sensor codes are required; Type A, MIL at once (19OBDG03D, 25OBDG03B). A slow or sticking pin, a worn shift groove or poor oil are therefore likelier culprits than wiring. CARB requires the lift system to catch cylinders running on the wrong cam profile.

Likely causes

Pin of actuator 2 sticking or slow (wear, sludge, wrong oil)
Worn shift groove or detent on the intake cam sleeve
Hall element in the actuator reporting implausible levels

Symptoms

  • MIL on at once
  • Engine kept on a fixed cam profile, no cylinder deactivation
  • Possible ticking from the camshaft carrier or slightly uneven idle

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–1,500
Time0.5–6 h

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

Parts involved

a camshaft profile actuator pos sensor b b1wiring harnessecm

Related codes

P2C06P2C09P2C0EP2C17

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