Engine

P037C — Cold Start Camshaft Profile System Performance

Severity: medium Drive with care, to a shop

What P037C means

During a cold start the ECM compares camshaft and crankshaft position signals and expects the camshaft profile or timing system to reach its commanded position. If the actual position does not match, it sets P037C. The cause can be a sensor, a VVT actuator, oil pressure problems, a stretched timing chain or an ECM software issue.

Symptoms

  • Check Engine light on
  • Rough idle after a cold start
  • Hesitation or reduced power
  • Misfires
  • Hard starting or stalling soon after startup

Possible causes

  1. Faulty camshaft position sensor or bad signal
  2. Low or poor quality oil affecting VVT actuators
  3. Stretched timing chain or misaligned timing
  4. Faulty VVT solenoid or phaser
  5. Damaged wiring or poor connector contact at the sensor
  6. ECM software issue

How to diagnose

  1. Scan all codes and freeze frame data and look for related camshaft or crankshaft sensor codes
  2. Check oil level, viscosity and condition, and change the oil and filter if needed
  3. Inspect sensor connectors and wiring, and test power, ground and signal
  4. Scope the camshaft sensor signal and compare it with the crankshaft signal
  5. Compare commanded and actual cam timing angles on a scan tool
  6. Test VVT solenoid operation and oil pressure
  7. Evaluate timing chain or belt condition and verify cam timing
  8. Check for available ECM software updates

Common fixes

  • Change the oil and filter with the specified grade
  • Replace the camshaft position sensor
  • Repair the wiring or connector
  • Replace the VVT solenoid or phaser
  • Replace the timing chain or belt with tensioners and set timing
  • Update the ECM software

Questions and answers

What does P037C mean?

It is a cold start camshaft profile system performance fault. The ECM sees that camshaft position or timing does not match what it commanded.

Can I drive with P037C?

Only carefully and for a short distance, such as to a repair shop. You may get power loss and misfires, and oil or timing chain problems can seriously damage the engine.

What should I check first?

Start with the oil level and condition, then inspect the camshaft sensor and its connector. If those are fine, check the VVT system and timing chain condition.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.