Fuel and air

P01D7 — Cylinder 7 Injection Timing Over-Retarded

Severity: medium Drive with care, to a shop

What P01D7 means

The engine control module compares the commanded and actual start of fuel injection for cylinder 7. When the injector opens noticeably later than planned, it sets P01D7. The cause is usually the injector, its wiring, or a fault in injection control. This code applies to engines with at least seven cylinders, such as V8s, V10s, V12s and diesels.

Symptoms

  • Check Engine light on
  • Rough idle
  • Reduced power and sluggish acceleration
  • Misfire or engine shudder
  • Higher fuel consumption
  • Harsh running or smoke, especially on diesels

Possible causes

  1. Faulty cylinder 7 injector (electrical or mechanical)
  2. Open, corroded or loose wiring or connector at injector 7
  3. Low fuel rail pressure
  4. ECM control signal error or software fault
  5. Air leak skewing the mixture
  6. Mechanical timing or fuel pump drive issue (uncommon)

How to diagnose

  1. Read all codes and freeze frame data, and note any injector or misfire codes.
  2. Review fuel trims and adaptation values and compare cylinder balance.
  3. Inspect the injector 7 connector and harness for corrosion, damage, loose locks or oil.
  4. Test injector resistance and the control signal with a meter or scope.
  5. Measure fuel pressure and compare it with specification.
  6. Check the intake and exhaust for leaks.
  7. Swap injector 7 with a neighbor to see if the fault follows it.
  8. Check for an ECM software update for your vehicle.

Common fixes

  • Replace or service the cylinder 7 injector
  • Repair the injector wiring or connector
  • Fix the cause of low fuel pressure (pump, filter, regulator)
  • Repair air leaks
  • Update or reflash the ECM software

Questions and answers

What does P01D7 mean?

Fuel injection in cylinder 7 starts later than the ECM commanded. The usual culprits are the injector, its wiring, or fuel pressure.

Can I drive with P01D7?

Briefly and gently, for example to a repair shop. Extended driving risks misfires and damage to the catalytic converter.

What should I check first?

Start with the injector 7 connector and wiring, then fuel pressure and fuel trims. These are the most common and cheapest causes.

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.