P02AD: Cylinder 5 - Injector Leaking

What it means

The control module detected fuel leakage from the cylinder 5 injector. The code identifies leakage but does not establish whether the nozzle, seal, or another part is responsible.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

The engine computer monitors whether cylinder 5's injector stops flowing fuel when commanded closed. This code sets when it detects fuel continuing to enter cylinder 5 beyond the calibrated leakage limit; the leak may be at the injector nozzle, internal valve, or seal.

Common causes

Most likely first.

1. Injector nozzle or internal valve leaking
2. Injector seat or seal leaking
3. Injector stuck open or control fault
4. Excess fuel pressure

Symptoms

• Check-engine light
• Rough idle or engine vibration
• Misfire or hesitation
• Fuel odor or increased fuel consumption

How to diagnose it

1. Review freeze-frame data and cylinder 5 misfire information, and note any fuel odor or difficult starting.
2. With the engine off, inspect cylinder 5 injector area and seals for visible fuel leakage; do not run the engine if fuel is leaking externally.
3. Check cylinder 5 injector wiring and control signals for a fault that could keep it energized.
4. Perform an injector leakage or balance test and compare cylinder 5 with the other cylinders.
5. Check fuel pressure and injector sealing against the manufacturer's specification.

Common fixes

• Replace a leaking cylinder 5 injector seal.
• Repair a cylinder 5 injector control or wiring fault that keeps the injector open.
• Replace a cylinder 5 injector that leaks internally or through its nozzle.
• Correct excessive fuel pressure if confirmed by testing.

Can I keep driving?

Do not drive if you smell strong fuel or see an external leak; shut the engine off and have the leak addressed. Otherwise, minimize driving because excess fuel can cause misfires, dilute engine oil, and damage the catalytic converter.