Sticking or sluggish cold start camshaft profile actuator or solenoid; Oil sludge or debris blocking the oil passages that feed the camshaft profile mechanism; Wiring damage or poor electrical connection at the camshaft profile solenoid; Failed camshaft position sensor or crankshaft position sensor giving inaccurate timing signals; Mechanical wear in the camshaft phaser or profile switching mechanism; Low engine oil level or incorrect oil viscosity preventing proper hydraulic operation

DTC codes / P03xx · Ignition system and misfire / P037C

P037CCold Start Camshaft Profile System Performance

Q: What does code P037C mean?

Cold Start Camshaft Profile System Performance. P037C indicates that the engine control module has detected a performance problem with the cold start camshaft profile system, which is designed to alter valve timing or lift during cold starts to improve emissions and idle quality. The computer monitors the camshaft position and compares the actual profile against the expected profile during a cold start, and it sets this code when the two do not match within a calibrated threshold.

P037C indicates that the engine control module has detected a performance problem with the cold start camshaft profile system, which is designed to alter valve timing or lift during cold starts to improve emissions and idle quality. The computer monitors the camshaft position and compares the actual profile against the expected profile during a cold start, and it sets this code when the two do not match within a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough or unstable idle immediately after a cold start
Extended cranking time before the engine starts when cold
Slight loss of power or hesitation during the first few minutes of driving
In rare cases, a noticeable ticking or tapping noise from the valvetrain on cold starts

Common causes, most likely first

Sticking or sluggish cold start camshaft profile actuator or solenoid
Oil sludge or debris blocking the oil passages that feed the camshaft profile mechanism
Wiring damage or poor electrical connection at the camshaft profile solenoid
Failed camshaft position sensor or crankshaft position sensor giving inaccurate timing signals
Mechanical wear in the camshaft phaser or profile switching mechanism
Low engine oil level or incorrect oil viscosity preventing proper hydraulic operation

How to diagnose and fix it

Check engine oil level and condition, and top up or change oil if it is low or degraded
Inspect the camshaft profile solenoid connector and wiring for corrosion, chafing, or loose pins
Test the camshaft profile solenoid for proper resistance and operation using a multimeter and scan tool
Remove and clean the camshaft profile solenoid and its oil screen to clear any sludge or debris
Verify camshaft and crankshaft position sensor signals with an oscilloscope to rule out timing signal errors
Perform a manufacturer-specific actuator test or relearn procedure for the cold start camshaft profile system
If the fault persists, inspect the camshaft phaser and profile switching mechanism for mechanical wear or damage

Cold start cam profile faults often misdiagnosed

A dirty or sludged oil control screen on the camshaft profile solenoid is a frequent culprit that many technicians overlook when replacing the solenoid itself.
This code can be set by a weak battery or low charging voltage during cold cranking, which causes the actuator to respond sluggishly and trigger a false performance fault.
Some vehicles require a specific cold-start relearn procedure after battery replacement or oil service, and skipping it can cause P037C to return even when all components are healthy.
A failing camshaft position sensor may not set its own code but can still cause P037C by providing erratic timing signals during the cold start window.
Aftermarket oil filters with poor anti-drainback valves can allow oil to drain from the profile mechanism overnight, causing a dry start and setting this code.

Can I keep driving with P037C?

The vehicle is generally safe to drive with P037C because the fault mainly affects cold start emissions and idle quality, but avoid heavy acceleration or towing until the issue is resolved. Prolonged driving with a sticking profile mechanism can lead to increased wear, so schedule a diagnosis soon.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.