P037CCold Start Camshaft Profile System Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- To heat the catalyst quickly after a cold start, some engines select a particular camshaft profile; CARB counts altered valve timing among these cold-start measures and requires components of the cold-start strategy to have their own diagnostics. P037C checks whether the requested profile is actually engaged during this phase. It is documented by code only at GM, on the 2.7-litre turbo four-cylinder (L3B) with a three-step sliding camshaft: while catalyst heating is active, the measured lift state is compared with the cold-start target, and if it is wrong in 100 of 120 cylinder events the code is set in the first trip. Two GM bulletins (19-NA-145 for 2019 Silverado/Sierra 1500 with stalling on remote start below −6 °C, 20-NA-174 for the 2020 Cadillac CT4) trace P037C to a software fault and reprogram the engine module.
- What you may notice
- Check engine light on
- Rough running or stalling when cold (for example on remote start)
- Often no noticeable symptoms
- Likely causes
- LikelyEngine module software (GM L3B, reprogramming)
- PossibleProfile actuator (sliding cam pin) sticking or not switching
- PossibleActuator circuit (connector, wiring)
- RareWrong oil viscosity or low oil level, mechanism stiff when cold
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.