Fuel and air

P01D6 — Cylinder 6 Injection Timing Over-Advanced

Severity: medium Drive with care, to a shop

What P01D6 means

P01D6 is set when the actual start of injection in cylinder 6 is earlier than the PCM commanded, beyond the allowed limit. The PCM compares the injection command with crankshaft and camshaft position signals and, where equipped, injector feedback. The code is most common on diesel and some direct-injection gasoline engines.

Symptoms

  • Check Engine light on
  • Rough idle or hesitation under throttle
  • Loss of power
  • Higher fuel consumption
  • Exhaust smoke, especially on startup
  • Knocking or harsh engine running
  • Misfire on cylinder 6

Possible causes

  1. Worn or out-of-spec injector on cylinder 6
  2. Faulty crankshaft or camshaft position sensor
  3. PCM software fault or outdated calibration
  4. Damaged wiring or a poor connection at the injector connector
  5. Fuel supply problem such as low or unstable pressure
  6. Air leak in the intake skewing the mixture
  7. Shifted valve timing from a stretched chain or belt

How to diagnose

  1. Read all codes and freeze frame data, noting other injector or position sensor codes
  2. Review fuel trims and per-cylinder balance or correction values
  3. Test fuel pressure at idle and under load
  4. Inspect the cylinder 6 injector harness and connector, and test the circuit for opens and shorts to ground
  5. Check crankshaft and camshaft sensor signals with a scope
  6. Verify cam-to-crank correlation and the condition of the timing chain or belt
  7. Swap the injector with a neighbor and see if the fault follows
  8. Check for a PCM software update for your vehicle

Common fixes

  • Replace or service the cylinder 6 injector
  • Replace a faulty crankshaft or camshaft position sensor
  • Repair the wiring or connector
  • Update the PCM software
  • Fix intake leaks and fuel supply issues
  • Correct or replace timing drive components

Questions and answers

Can I drive with P01D6?

Only for a short distance and under light load to reach a shop. Over-advanced injection can damage pistons and the exhaust system.

What most often causes P01D6?

Most often it is the cylinder 6 injector or its wiring. Also check the position sensors and look for a PCM update.

Is clearing the code enough?

No. If the cause remains, the code will return and the engine will keep running with incorrect injection timing.

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.