Faulty or sticking cylinder 12 fuel injector, or an injector with drifted timing or response; Wiring or connector fault in the cylinder 12 injector circuit, such as high resistance, chafing or corrosion; Incorrect or unstable fuel rail pressure affecting injection timing, from a pressure sensor, regulator or pump problem; Camshaft or crankshaft position sensor signal fault or timing correlation error; Mechanical timing fault, such as a stretched or jumped timing chain or belt, or a phasing fault; Outdated or faulty engine control unit software or calibration, where the manufacturer has documented this; Internal ECU driver fault for the cylinder 12 injector.

P01E2

Cylinder 12 Injection Timing Performance - Over Advanced.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
1: AreaFuel and air metering
E2: FaultThe specific fault in that area

What it means

P01E2 means the engine control unit has found that the injection timing for cylinder 12 is more advanced than commanded, so the fuel is being injected earlier than the target. The ECU compares actual or measured injection timing against the demanded value and sets the code when the difference exceeds its limit for long enough. It applies to engines with at least twelve cylinders, and the exact monitoring method depends on the engine.

Symptoms

Engine management warning light on
Rough running or misfire, especially on one bank
Knocking or harsh diesel-like combustion noise
Reduced power or the engine going into a limp mode
Increased exhaust smoke or a strong fuel smell
Hard starting or uneven idle

Possible causes

Faulty or sticking cylinder 12 fuel injector, or an injector with drifted timing or responselikely
Wiring or connector fault in the cylinder 12 injector circuit, such as high resistance, chafing or corrosionlikely
Incorrect or unstable fuel rail pressure affecting injection timing, from a pressure sensor, regulator or pump problempossible
Camshaft or crankshaft position sensor signal fault or timing correlation errorpossible
Mechanical timing fault, such as a stretched or jumped timing chain or belt, or a phasing faultpossible
Outdated or faulty engine control unit software or calibration, where the manufacturer has documented thisrare
Internal ECU driver fault for the cylinder 12 injectorrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine speed, load, temperature and rail pressure when the fault set, and look for related injector, rail pressure or position sensor codes.
Check for relevant technical service bulletins and software updates for the specific model and engine.
Inspect the cylinder 12 injector connector and wiring for damage, corrosion, loose pins, oil or coolant contamination and chafing.
Compare live data for injection timing, rail pressure demand against actual, and cylinder balance or misfire counters for cylinder 12 against the other cylinders.
Check the crankshaft and camshaft sensor signals and their correlation, and check the sensors and wiring.
Test the injector circuit electrically for resistance, supply and control signal, following the manufacturer's procedure for the engine.
Perform an injector function or balance test and compare cylinder 12 with the others.
If the electrical and fuel checks pass, check mechanical timing and phasing against the manufacturer's specification.

How to fix

Repair or replace damaged wiring or connectors in the cylinder 12 injector circuit.
Replace the cylinder 12 injector if it is confirmed faulty, and code or adapt it as the manufacturer requires.
Correct fuel pressure faults by repairing or replacing the faulty sensor, regulator or pump component.
Replace a faulty crankshaft or camshaft position sensor, or repair its wiring.
Correct mechanical timing faults, such as a worn chain or belt, tensioner or phasing component.
Update the ECU software or calibration only where an outdated or faulty version is a known cause for that model.

Can I keep driving?

High severity

Avoid driving beyond what is needed to reach a workshop. Over-advanced injection timing can cause harsh combustion and engine damage, so stop driving if you hear knocking, notice a misfire or the car loses power.

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