P01CD

What it means

P01CD is the generic code for cylinder 2 injection timing performance being over retarded. The engine control unit has compared the commanded start of injection for cylinder 2 with the timing it measured or inferred, and found the actual injection occurring later than commanded by more than the permitted amount. It is mainly seen on diesel or direct injection engines, and the exact monitoring method depends on the model and engine.

Symptoms

• Engine management light on
• Rough idle or misfire on cylinder 2
• Hard starting or extended cranking
• Loss of power or poor throttle response
• Excess smoke, especially white or grey on a diesel
• Increased fuel consumption or knocking noise

Possible causes

• Faulty or sticking cylinder 2 injector, or one with a worn or slow-responding internal mechanismlikely
• Wiring or connector fault on the cylinder 2 injector circuit, such as high resistance, corrosion or a poor pin fitlikely
• Low or unstable fuel pressure from a weak supply or high-pressure pump, restricted filter or air in the fuelpossible
• Crankshaft or camshaft position signal fault or timing drift, such as a stretched chain or worn beltpossible
• Contaminated or poor quality fuel affecting injector responsepossible
• Fault in the engine control unit injector driver or outdated calibration, where a known issue exists for that enginerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine speed, load, fuel pressure and temperature when the code set, and check for related misfire or fuel pressure codes.
2. Check for relevant technical service bulletins or known issues for the specific engine, as injector monitoring varies between models.
3. Inspect the cylinder 2 injector connector and wiring for damage, corrosion, chafing, loose pins and oil or coolant contamination.
4. Check the fuel level, fuel quality and fuel filter condition, and look for signs of air ingress or leaks in the supply side.
5. Compare live data for fuel rail pressure actual versus requested, and check injector correction or balance values for cylinder 2 against the other cylinders.
6. Test the injector circuit resistance and driver signal at the connector against the manufacturer specification.
7. Check crankshaft and camshaft sensor signals and confirm the valve timing is correct, following the procedure for that engine.
8. Perform an injector leak-off or flow test where the engine design allows, per manufacturer procedure.

How to fix

• Repair or replace damaged wiring or connectors on the cylinder 2 injector circuit.
• Replace the cylinder 2 injector if testing shows it is faulty, and carry out any required coding or adaptation for the new part.
• Replace a blocked fuel filter, correct any air leaks and repair low fuel pressure faults in the supply or high-pressure pump.
• Correct valve or injection timing faults, replacing a worn chain, belt or tensioner as needed, and replace faulty crank or cam sensors.
• Drain and replace contaminated fuel and clean the system as required.
• Apply an updated control unit calibration only if the manufacturer lists it as a fix for this fault on that engine.

Can I keep driving?

Nearby codes

• P01CCGenericCylinder 1 Injection Timing Performance - Over Advanced
• P01CEGenericCylinder 2 Injection Timing Performance - Over Advanced