P2C12 code meaning
B Camshaft Profile Actuator Position Sensor A Circuit Bank 1
Powertrain system Generic code P2Cxx codes Check engine light
What P2C12 means
Camshaft B is the exhaust camshaft in J2012 terms, and P2C12 reports an open circuit in the feedback of its first profile actuator on bank 1. GM's 2.7 L turbo L3B (Silverado and Sierra 1500 from model year 2019) is the documented user: its tables call this element exhaust Hall sensor 1. With the driver energised, the ECM flags a break once the signal-to-ground impedance reaches 200 kilohms or more; four failures out of five samples at system voltage above 11 V give a Type A code, MIL on trip one (19OBDG03D, 25OBDG03B). P2C12 is in the main DTC list of PIT5677 and its successor 21-NA-149, which point to engine harness damage at the camshaft carrier cover. Exhaust lift changes are then suspended. Low and high: P2C14, P2C15.
P2C12 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2C12
- Check engine light from the first trip
- Exhaust cam profile no longer switched, fuel economy mode unavailable
- With harness damage, several other engine codes at the same time
Common causes of P2C12
- Most likelyEngine harness worn through where it crosses the camshaft carrier cover (GM PIT5677, 21-NA-149)
- PossibleConnector on exhaust actuator 1 not latched or corroded
- Less likelyOpen Hall element inside the exhaust actuator
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
B camshaft profile actuator pos sensor a b1Wiring harnessECM
What each part of P2C12 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| C | Area: hybrid propulsion. |
| 12 | The exact fault in that area. |
What to do next
- Note P2C12 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2C12
What does P2C12 mean?
P2C12 means "B Camshaft Profile Actuator Position Sensor A Circuit Bank 1". Camshaft B is the exhaust camshaft in J2012 terms, and P2C12 reports an open circuit in the feedback of its first profile actuator on bank 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P2C12?
Drive gently and only to a workshop. With P2C12 the car can go into limp mode (reduced power) to protect itself.
Will P2C12 fail an emissions test?
Yes, it can. P2C12 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2C12 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2C12 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.