P02BF - Cylinder 9 – Fuel Trim Offset at High Limit

P02BF is triggered when the Engine Control Unit (ECU) detects that the fuel trim adjustment for cylinder 9 has reached its maximum positive limit. This signifies that the ECU is attempting to compensate for an extremely lean condition (too little fuel relative to air) by increasing the injector pulse width, yet the desired stoichiometric ratio is not achieved. The monitor uses crankshaft speed fluctuations (misfire detection logic) to evaluate individual cylinder power contribution. This condition often results in increased emissions and potential damage to the aftertreatment system if left unaddressed.