Fuel and air

P01CD — Cylinder 2 Injection Timing Over-Retarded

Severity: medium Drive with care, to a shop

What P01CD means

The engine control module compares the actual start of fuel injection on cylinder 2 with the calculated target. P01CD sets when injection begins too late compared to that target. It is most often seen on diesel and direct-injection engines, where injection timing is tightly monitored.

Symptoms

  • Check engine light on
  • Rough idle or vibration
  • Reduced power and sluggish acceleration
  • Possible misfire on cylinder 2
  • Increased fuel consumption
  • Harsh or noisy engine running

Possible causes

  1. Faulty, clogged or sticking fuel injector on cylinder 2
  2. Low fuel pressure from a weak pump, bad regulator or clogged filter
  3. Damaged wiring or poor connection at the injector or related sensors
  4. Intake or exhaust leak skewing the air-fuel mixture
  5. ECM software or calibration problem
  6. Faulty sensor used to determine injection timing

How to diagnose

  1. Scan all codes and freeze-frame data, and note any other fuel or misfire codes
  2. Review short- and long-term fuel trims and adaptation values
  3. Compare cylinder balance or contribution readings
  4. Measure fuel pressure and compare with the manufacturer's spec
  5. Inspect the cylinder 2 injector connector and harness, and test the circuit for opens and shorts to ground or power
  6. Test the injector: resistance, drive signal pattern, leakage and spray
  7. Check the intake and exhaust for leaks
  8. Look for ECM software updates for your vehicle

Common fixes

  • Clean or replace the cylinder 2 injector
  • Repair fuel delivery faults: pump, filter or pressure regulator
  • Repair the injector wiring or connector
  • Fix the air or exhaust leak
  • Update or reflash the ECM if the manufacturer offers it

Questions and answers

What does P01CD mean?

The ECM sees fuel injection on cylinder 2 starting later than it should. The cause is usually the injector, fuel pressure or an electrical circuit problem.

Can I drive with code P01CD?

Briefly and carefully, to get to a repair shop. Extended driving can cause power loss, poor fuel economy and higher emissions.

How do I clear P01CD?

Clearing only makes sense after the cause is fixed. If the fault remains, the code will usually return within a few drive cycles.

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.