DTC 1-1-3 Short Term Fuel Trim, Upper Limit

1-1-3 SHORT TERM FUEL TRIM (INTEGRATOR), UPPER LIMIT

Condition(s) for DTC
The short term fuel trim value is a measure of the manner in which the injection period included in the basic MFl module program must be varied to ensure that the engine is supplied with the optimum air/fuel mixture. This optimum mixture corresponds to a value of Lambda = 1. If the engine is running lean, the short term fuel trim will extend the injection period to restore the optimum mixture. A DTC will be recorded if the engine runs so lean that the short term fuel trim reaches its upper limit and remains there for 166 seconds.

Substitute value
^ None.

Fault source(s)
^ Heated Oxygen Sensor signal lead short-circuited to ground.
^ Heated Oxygen Sensor faulty.
^ Contact resistance and oxidation in Mass Air Flow Sensor connector.
^ Mass Air Flow Sensor faulty.

Fault symptom(s)
^ Fault may cause high fuel consumption and driving problems.