P2E5A: Cylinder 2 Alternative Fuel Misfire Detected

What it means

Misfire detected on cylinder 2 during alternative fuel operation. Specific to bi-fuel CNG/LPG operation.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The engine controller looks for crankshaft speed changes that indicate incomplete combustion while alternative fuel is in use. This code assigns the misfire to cylinder 2, focusing diagnosis on cylinder 2's alternative-fuel injector and its electrical connection.

Common causes

Most likely first.

1. Injector clogged or weak
2. Fuel quality off-spec

Symptoms

• Check engine light on or flashing
• Rough idle and uneven running
• Power loss, hesitation under acceleration
• Increased fuel consumption
• Possible smell of unburned fuel from exhaust

How to diagnose it

1. Read freeze-frame data and per-cylinder misfire counts to confirm that cylinder 2 is implicated during alternative-fuel operation.
2. Check whether cylinder 2 runs normally on petrol; a fault confined to alternative fuel points toward its alternative-fuel delivery.
3. Inspect the cylinder 2 alternative-fuel injector connector and harness for damage, corrosion, looseness, or leakage.
4. Verify alternative-fuel quality and supply conditions, noting whether the fault began after refuelling or appears mainly under load.
5. Test cylinder 2's alternative-fuel injector and compare its operation with the other injectors and the manufacturer's specification.
6. If the misfire remains on petrol, inspect cylinder 2 ignition and mechanical condition as well.

Common fixes

• Repair damaged or loose wiring at the cylinder 2 alternative-fuel injector.
• Replace suspect alternative fuel with known-good fuel if quality is questionable.
• Clean or replace the cylinder 2 alternative-fuel injector if testing confirms weak or restricted flow.
• Correct a confirmed alternative-fuel pressure regulation or supply fault.

Can I keep driving?

Limit driving and avoid high loads; stop if the check-engine light flashes or the engine runs very roughly, since a persistent misfire can overheat the catalytic converter. If petrol operation is smooth, switch to it if possible and arrange prompt diagnosis.