P02AF: Cylinder 6 - Fuel Trim at Min Limit

What does P02AF mean?

These codes belong to an individual-cylinder fuel correction: a diesel's cylinder balance control measures each cylinder's crankshaft acceleration and adjusts its injection quantity; on petrol engines a cylinder-selective mixture control does the same. CARB requires the system to report when such a correction has used up its range or one cylinder causes an imbalance. P02AF means the correction for cylinder 6 is at its lower limit: the module keeps taking fuel away from this cylinder and still cannot even it out – a sign that it receives too much fuel, for example from a dripping injector. GM and Ford use other codes for this (P0263 ff, P219A ff); no manufacturer document describing this code with thresholds was found, so the description follows CARB and published patents.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Rough idle, vibration
• Higher consumption, smoke or fuel smell

Common causes

• High Injector of cylinder 6 dripping or leaking
• Medium Injector with excessive flow (worn seat or needle)
• Low Wrong injector correction code after replacement
• Low Injector circuit short (extended activation)

Likelihood is a general estimate across vehicles; your make and model may differ.