Fuel and air

P020A — Cylinder 1 Injection Timing Fault

Severity: medium Drive with care, to a shop

What P020A means

P020A means the engine control module found that fuel injection timing for cylinder 1 is outside the expected range. The module normally calculates timing from the crankshaft and camshaft sensor signals and fires the injector accordingly. If the injector response or the sensor input does not match that calculation, the code is stored and the check engine light comes on.

Symptoms

  • Check engine light on
  • Rough idle or vibration
  • Misfire on cylinder 1
  • Reduced power and hesitation on acceleration
  • Higher fuel consumption
  • Hard starting or unstable idle
  • Increased exhaust emissions

Possible causes

  1. Faulty cylinder 1 fuel injector
  2. Open, shorted or corroded injector wiring or connector
  3. Failing crankshaft or camshaft position sensor
  4. Fuel supply problem such as low pressure or a clogged filter
  5. Intake air leak upsetting the mixture
  6. Mechanical timing issue such as a stretched chain or jumped belt
  7. PCM fault or outdated software (rare)

How to diagnose

  1. Scan all codes and freeze frame data, noting any misfire or crank/cam sensor codes.
  2. Inspect the cylinder 1 injector connector and harness for damage, moisture and corrosion.
  3. Measure injector coil resistance and compare it with specifications.
  4. Check the injector signal with a scope or noid light for a clean, steady pulse.
  5. Review fuel trims and cylinder balance data on a scan tool.
  6. Test fuel pressure and check the filter and pump.
  7. Look for intake or exhaust leaks.
  8. Test the crankshaft and camshaft sensors and verify mechanical timing.

Common fixes

  • Clean or replace the cylinder 1 injector
  • Repair damaged wiring or connectors
  • Replace a faulty crankshaft or camshaft sensor
  • Correct fuel pressure problems or air leaks
  • Repair or replace worn timing components
  • Update software or replace the PCM only after other causes are ruled out

Questions and answers

What does P020A mean?

It means the engine computer detected a timing error in fuel injection for cylinder 1. The injector is not firing when the module expects it to.

Can I drive with P020A?

Only briefly and gently, such as to a repair shop. Misfires can damage the catalytic converter and the engine will lose power.

What should I check first?

Start with the cylinder 1 injector wiring and connector, then test the injector, fuel pressure and the crankshaft and camshaft sensors.

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.