Faulty fuel injector for cylinder 12, such as a sticking nozzle or internal leakage; Wiring harness damage or poor electrical connection at the cylinder 12 injector; Failed camshaft position sensor or crankshaft position sensor providing inaccurate timing signals; Sticking or contaminated oil control valve affecting variable valve timing on the bank containing cylinder 12; Engine control module software calibration issue or internal fault; Mechanical timing chain or belt wear causing incorrect cam-to-crank correlation; Low fuel pressure or restricted fuel supply affecting injection timing

DTC codes / P01xx · Fuel and air metering / P01E2

P01E2Cylinder 12 Injection Timing Performance - Over Advanced

Q: What does code P01E2 mean?

Cylinder 12 Injection Timing Performance - Over Advanced. P01E2 indicates that the engine control module has detected the fuel injection timing for cylinder 12 is more advanced than the commanded value during operation. The computer compares the actual injection event timing, often via crankshaft and camshaft position signals, to the desired timing and sets this code when the deviation exceeds a calibrated threshold.

P01E2 indicates that the engine control module has detected the fuel injection timing for cylinder 12 is more advanced than the commanded value during operation. The computer compares the actual injection event timing, often via crankshaft and camshaft position signals, to the desired timing and sets this code when the deviation exceeds a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaFuel and air metering

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire sensation, especially when the engine is cold
Reduced engine performance or sluggish acceleration
Increased fuel consumption
Occasional hard starting or extended cranking
Engine knock or pinging under load

Common causes, most likely first

Faulty fuel injector for cylinder 12, such as a sticking nozzle or internal leakage
Wiring harness damage or poor electrical connection at the cylinder 12 injector
Failed camshaft position sensor or crankshaft position sensor providing inaccurate timing signals
Sticking or contaminated oil control valve affecting variable valve timing on the bank containing cylinder 12
Engine control module software calibration issue or internal fault
Mechanical timing chain or belt wear causing incorrect cam-to-crank correlation
Low fuel pressure or restricted fuel supply affecting injection timing

How to diagnose and fix it

Perform a visual inspection of the cylinder 12 injector connector and wiring for chafing, corrosion, or loose pins
Use a scan tool to check for related camshaft and crankshaft position sensor codes and freeze-frame data
Measure the resistance of the cylinder 12 injector and compare it to the manufacturer's specification
Check fuel pressure and injector balance to rule out fuel delivery issues
Verify engine timing marks and inspect the timing chain or belt for wear or skipped teeth
Test the variable valve timing solenoid and oil control valve for proper operation
If all else checks out, reflash or replace the engine control module as a last resort

Before you replace the cylinder 12 injector

A dirty or failing mass airflow sensor can skew fuel trim and indirectly cause injection timing deviations that set this code, so check fuel trims first.
The code may be set by a momentary glitch in the camshaft position sensor signal that does not leave a permanent sensor code, so inspect the sensor wiring carefully.
On engines with variable valve timing, a sludged oil control valve can retard or advance cam timing enough to trigger P01E2 without any other VVT codes.
A weak battery or poor ground connection can cause the ECM to misinterpret timing signals, so always verify battery and ground integrity before condemning components.
P01E2 is often misdiagnosed as a simple injector failure when the real cause is a stretched timing chain that has shifted cam timing on that bank.

Can I keep driving with P01E2?

You can drive the vehicle short distances to a repair shop, but avoid heavy acceleration and towing because advanced injection timing can lead to engine knock and potential damage. If the check engine light is flashing or the engine runs very poorly, stop driving and seek immediate professional diagnosis.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.