Fault description

Diagnosis monitors the signal voltage of the oxygen sensor 2 after catalytic converter after overrun mode.

The fault is detected when the signal gradient from lean to rich is less than a threshold.

Possible fault cause:

• line disconnection;
• short to B+, sensor stops (with help from a voltage source) at U > 0.2V;
• Sensor too cold after overrun fuel cutout (only possible in extreme situations)
• Impact through the catalyst in the case of critical fuel
• EGO sensor strongly altered