Fuel and air

P020D — Cylinder 4 Injection Timing Control Malfunction

Severity: medium Drive with care, to a shop

What P020D means

The engine control module sets when and for how long each injector opens, and it monitors whether the command is carried out. P020D means the injection control for cylinder 4 does not match what is expected. The injector, its circuit or the timing reference signals may be at fault, so the cylinder can get the wrong amount of fuel at the wrong moment.

Symptoms

  • Check Engine light on
  • Rough idle or misfire on cylinder 4
  • Hesitation and weak acceleration
  • Higher fuel consumption
  • Hard starting or long cranking
  • Increased exhaust emissions

Possible causes

  1. Faulty cylinder 4 fuel injector
  2. Open, shorted or corroded wiring or connector at injector 4
  3. Injector driver circuit fault inside the ECM
  4. Crankshaft or camshaft position sensor fault
  5. Fuel supply or rail pressure problem (especially on diesels)
  6. Air leak upsetting the air-fuel mixture

How to diagnose

  1. Scan all codes and freeze-frame data, and look for crank or cam sensor codes
  2. Inspect the injector 4 connector and harness for chafing, corrosion and loose pins
  3. Review fuel trims and cylinder balance data
  4. Measure injector coil resistance and compare it with the other injectors
  5. Check for a control signal at the injector with a scope or noid light
  6. Test fuel pressure against specification
  7. Check the intake and exhaust for leaks
  8. Swap the injector with a neighboring cylinder and see if the fault follows

Common fixes

  • Replace or clean the cylinder 4 injector
  • Repair the injector wiring or connector
  • Replace a faulty crankshaft or camshaft sensor
  • Fix the air leak or fuel supply problem
  • Replace or reflash the ECM only after the driver fault is confirmed

Questions and answers

What does P020D mean?

It is a cylinder 4 injection control fault: the ECM sees that injector timing or operation does not match its command. The injector or its wiring is the most common culprit.

Can I drive with P020D?

Only in a limited way, such as to a nearby shop. A misfire can harm the catalytic converter and engine, so do not put off the repair.

How do I tell an injector fault from an ECM fault?

Check the wiring and injector resistance, then swap the injector with a neighbor. If the code moves to the other cylinder, the injector is bad. The ECM is the last suspect.

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.