Powertrain, generic (extended)

P2C17 B Camshaft Profile Actuator Position Sensor B Range/Performance Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C17 flags implausible feedback from exhaust Hall sensor 2, the position sensor of the second exhaust profile actuator on bank 1 of GM's L3B. The electrical circuit tests pass, yet the shift pattern is wrong: after a command GM expects the reading to pass below 55 (pin extending), below 45 (pin fully out) and back above 68 (pin retracted). A missing step, or a pin event reported without any command, counts as a failure; four such readings in five, with the motor turning, supply over 11 V and crank and cam sensors fault-free, lead to a Type A code, MIL straight away (19OBDG03D, 25OBDG03B). The harness bulletins only carry P2C17 in their keyword lists. Because CARB requires a single lift pin that fails to move to be caught, the engine falls back to a fixed exhaust profile. Look at oil condition and actuator 2 first.

Likely causes

Pin of exhaust actuator 2 binding because of deposits or degraded oil
Exhaust cam sleeve not snapping into its detent, worn groove
Low or aerated engine oil slowing the shift

Symptoms

  • Warning lamp on without delay
  • Engine runs on a fixed exhaust profile, no cylinder deactivation
  • Possibly a light tapping noise from the valve train

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

b camshaft profile actuator pos sensor b b1wiring harnessecm

Related codes

P2C13P2C16P2C18P2C19P2C0AP2B51

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