October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.
Fuel Trim System Operation
The fuel trim system monitors the averages of short-term and long-term fuel trim values. If these fuel trim values stay at the limits for a calibrated period of time, a malfunction is indicated. The fuel trim diagnostic compares the average of short and long-term fuel trim values. If either value is within the thresholds, a pass is recorded. If either value is outside the thresholds, a rich or lean fuel trim DTC will set.