P037C code meaning
Cold Start Camshaft Profile System Performance
Powertrain system Generic code P03xx codes Check engine light
What P037C means
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.
P037C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P037C
- Check engine light on
- Rough running or stalling when cold (for example on remote start)
- Often no noticeable symptoms
Common causes of P037C
- Most likelyEngine module software (GM L3B, reprogramming)
- PossibleProfile actuator (sliding cam pin) sticking or not switching
- PossibleActuator circuit (connector, wiring)
- Less likelyWrong oil viscosity or low oil level, mechanism stiff when cold
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Camshaft profile actuatorSliding camshaftEngine control module
What each part of P037C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 3 | Area: ignition system or misfire. |
| 7C | The exact fault in that area. |
What to do next
- Note P037C 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 P037C
What does P037C mean?
P037C means "Cold Start Camshaft Profile System Performance". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P037C?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P037C fail an emissions test?
Yes, it can. P037C 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 P037C to fix?
Difficulty: medium. A typical repair takes 0.5 to 5 hours of work. This is a job for a workshop.
Will P037C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.