Monitoring Function

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2010 BMW M6, 2010 BMW M5, 2009 BMW M6, 2009 BMW M5, and 2008 BMW M6. However, it is still accessible from the selected car via links, so may be relevant.

If the fuel system is suddenly and significantly disturbed (e.g. by a leaky injection valve) and the A/F controller reaches its restriction or a permanent deviation from the mean position reaches the additional lean or rich thresholds and the accumulated time (sum of all excesses for rich and lean) is greater than a fixed limit during a defined period, a fault for long term trim will be detected and stored.

If a lean condition is present and total fuel control is above the calibrated threshold a timer is started. If the lean threshold counter exceeds the calibrated threshold within the diagnostic time, a lean error is set.

If a rich condition is present and total fuel control is below the calibrated threshold a timer is started. If the rich threshold counter exceeds the calibrated threshold within the diagnostic time, a rich error is set.