Faulty or sticking fuel injector on cylinder 11 (slow response or poor opening); Wiring or connector fault in the cylinder 11 injector circuit (high resistance, corrosion, chafing); Low or unstable fuel pressure from a weak pump, blocked filter or failing pressure regulation; Fault with the crankshaft or camshaft position sensor signal affecting timing reference; Contaminated or poor quality fuel affecting injector operation; Injector driver fault or internal fault in the engine control unit; Mechanical timing fault such as stretched timing chain or incorrect valve timing, depending on engine design.

P01DF

Cylinder 11 Injection Timing Performance - Over Retarded.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
DF: FaultThe specific fault in that area

What it means

P01DF is a generic code meaning the engine control unit has found that the injection timing for cylinder 11 is over-retarded, so fuel is being delivered later than commanded. It sets when the measured or inferred injection timing for that cylinder deviates beyond the allowed limit in the retarded direction. This code only applies to engines with at least 11 cylinders, and the way timing is monitored depends on the engine and fuel system.

Symptoms

Engine management warning light on
Rough running or misfire, particularly on one cylinder bank
Loss of power or poor acceleration
Increased exhaust smoke or a strong fuel smell
Hard starting or uneven idle
Higher fuel consumption

Possible causes

Faulty or sticking fuel injector on cylinder 11 (slow response or poor opening)likely
Wiring or connector fault in the cylinder 11 injector circuit (high resistance, corrosion, chafing)likely
Low or unstable fuel pressure from a weak pump, blocked filter or failing pressure regulationpossible
Fault with the crankshaft or camshaft position sensor signal affecting timing referencepossible
Contaminated or poor quality fuel affecting injector operationpossible
Injector driver fault or internal fault in the engine control unitrare
Mechanical timing fault such as stretched timing chain or incorrect valve timing, depending on engine designrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, looking for related misfire, fuel pressure or sensor codes
Check for technical service bulletins and known issues for the specific engine and fuel system
Visually inspect the cylinder 11 injector wiring and connector for damage, corrosion, oil ingress or poor pin tension
Check fuel quality and the condition of the fuel filter, and consider recent refuelling history
Monitor live data for fuel pressure, injection timing and misfire counters on cylinder 11 compared with other cylinders
Check crankshaft and camshaft sensor signals and their correlation, plus the condition of the sensors and wiring
Test the injector circuit resistance and driver signal, and compare the injector's electrical and flow performance with specification
Check mechanical timing condition if no electrical or fuel cause is found, following the procedure for the specific engine

How to fix

Repair or replace damaged wiring or connectors in the cylinder 11 injector circuit
Replace the cylinder 11 injector if it is faulty, and carry out any required coding or adaptation for that engine
Replace the fuel filter and correct any low fuel pressure fault found in the pump or regulation
Replace a faulty crankshaft or camshaft position sensor, or repair its wiring
Drain and replace contaminated fuel and clear the system as required
Repair mechanical timing faults or update the control unit software if a known calibration issue applies to that engine

Can I keep driving?

Medium severity

The car can usually be driven a short distance to a workshop, but have it checked soon. Avoid heavy loads and hard acceleration, and stop if misfiring becomes severe, as unburnt fuel can damage the catalytic converter and engine.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.