P02D6

What it means

P02D6 is a generic powertrain code meaning the engine control unit has learned an offset for the cylinder 6 fuel injector (injector A) and that learned value has reached its minimum limit. The offset is an adaptive correction to injector delivery or timing, so the ECU saw that cylinder 6 needed the maximum amount of correction in one direction and could not trim any further. How the offset is calculated and what counts as the minimum limit depends on the engine and fuelling system.

Symptoms

• Engine warning light on
• Rough idle or uneven running, mainly on cylinder 6
• Misfire or hesitation under load
• Poor fuel economy or noticeable change in fuel consumption
• Increased exhaust smoke or fuel smell
• Reduced power or the car entering limp mode in some cases

Possible causes

• Cylinder 6 injector worn, sticking, leaking or delivering outside its tolerancelikely
• Wiring or connector fault at the cylinder 6 injector circuit, such as high resistance, corrosion or chafingpossible
• Mechanical problem on cylinder 6 affecting combustion, such as low compression or a worn valve or ringpossible
• Fuel pressure or fuel quality problem causing the injector to be trimmed to its limitpossible
• Recently fitted injector whose correction data was not coded or learned correctly, where the engine requires itpossible
• Faulty injector driver in the engine control unit or outdated softwarerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine load, temperature and rpm when the code set, and check for other injector, misfire or fuel trim codes
2. Check service history for recent injector replacement or fuel system work, and see whether the model requires injector codes or correction values to be entered
3. Inspect the cylinder 6 injector connector and wiring for damage, corrosion, oil contamination and loose pins
4. Look at live data for cylinder 6 injector corrections, misfire counts and fuel trims, and compare with the other cylinders
5. Check fuel pressure against the manufacturer specification, and consider the quality and age of the fuel
6. Measure the injector circuit resistance and check the injector for leakage or poor spray pattern, following the procedure for your engine
7. Carry out a compression or leak-down test on cylinder 6 if the injector appears healthy
8. Check for an applicable software update for the engine control unit for your model

How to fix

• Replace the cylinder 6 injector if it is out of tolerance, and code or adapt it as the manufacturer requires
• Repair or replace damaged wiring or connectors in the injector circuit
• Correct any fuel pressure fault found, such as a failing pump, regulator or blocked filter
• Drain and replace poor quality or contaminated fuel
• Repair the underlying engine mechanical fault on cylinder 6 if found
• Clear the code and complete a drive cycle after repair to confirm the learned offset returns to a normal range, and update the ECU software only if a known fault is documented

Can I keep driving?

Nearby codes

• P02D5GenericCylinder 5 Fuel Injector A Offset Learning At Max Limit
• P02D7GenericCylinder 6 Fuel Injector A Offset Learning At Max Limit