P02AE
Cylinder 6 - Fuel Trim at Max Limit.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 2
- AreaFuel and air metering (injector circuit)
- AE
- FaultThe specific fault in that area
What it means
P02AE means the engine control unit has reached the limit of the fuel trim correction it can apply to cylinder 6 alone. It sees that cylinder's air-fuel mixture is persistently too lean or too rich and cannot correct it any further. How the trim is calculated for each cylinder depends on the engine and control strategy, so check the manufacturer's data for the specific model.
Symptoms
- Engine management light on
- Rough idle or misfire-like shake
- Hesitation or poor response under load
- Higher fuel consumption or a fuel smell from the exhaust
- Possible additional misfire or fuel trim codes stored
Possible causes
- Faulty or leaking fuel injector on cylinder 6 (clogged, sticking or dripping)likely
- Vacuum or intake leak near cylinder 6, such as a cracked inlet manifold gasket or runner seal, or a split hoselikely
- Wiring or connector fault on the cylinder 6 injector circuit, giving high resistance or intermittent operationpossible
- Mechanical problem on cylinder 6, such as low compression, a leaking valve or a worn or carbon-fouled intake valvepossible
- Ignition fault on cylinder 6 (worn spark plug, weak coil) causing unburnt oxygen or fuel that distorts the mixture readingpossible
- Exhaust leak or faulty oxygen or air-fuel ratio sensor affecting the reading for that cylinder bankrare
- Outdated or faulty engine control unit software where the manufacturer has a known fixrare
How to diagnose
- Read all stored and pending codes and the freeze frame data. Note whether trim was lean or rich, plus engine load, temperature and speed when the code set.
- Check for related codes such as misfires, injector circuit faults, or bank fuel trim and oxygen sensor codes, and fix those first.
- Visually inspect the cylinder 6 injector connector, wiring and nearby intake hoses and gaskets for damage, looseness, splits or oil contamination.
- Check live fuel trim data at idle and at 2,500 rpm. If the trim improves with revs, suspect a vacuum leak. If it gets worse, suspect fuel delivery or an injector fault.
- Perform a smoke test of the intake system to find leaks around cylinder 6.
- Check the resistance of the cylinder 6 injector against the specification, and check the injector driver signal or operation against a known good injector.
- Inspect the spark plug and coil on cylinder 6, then carry out a compression or leak-down test if the mixture problem persists.
- Check fuel pressure against the manufacturer's specification, and check whether a software update is listed for this model and engine.
How to fix
- Replace or professionally clean and flow-test the faulty cylinder 6 injector.
- Repair or replace leaking intake manifold gaskets, seals or vacuum hoses.
- Repair damaged wiring or clean and secure the injector connector.
- Replace the worn spark plug or faulty ignition coil on cylinder 6.
- Repair the mechanical fault found, such as a valve or sealing problem, or clean intake valve deposits if the manufacturer specifies it.
- Apply a manufacturer software update only if one is documented for this fault.
Can I keep driving?
Short, gentle journeys are usually acceptable, but get it checked soon because a persistently wrong mixture can cause misfires and damage the catalytic converter. Stop driving if the engine runs very roughly, the light flashes or you smell raw fuel.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.