DTC 2-3-1 Long Term Fuel Trim, Part Load, Lower Limit

2-3-1 LONG TERM FUEL TRIM, PART LOAD, LOWER LIMIT

5-1-1 LONG TERM FUEL TRIM, IDLING, LOWER LIMIT

Condition(s) for DTCs
^ The MFI module receives information from the Heated Oxygen Sensor (HO2S) if the air/fuel mixture is too rich in the idling range (5-1-1) or in the part-load range (2-3-1). In this case, the HO2S signal will usually be over 0.5 Volts. The MFI module short term fuel trim compensates for this by making the mixture leaner so as to maintain a value of Lambda = 1. Deviation of the short term fuel trim mid-setting from its normal value will be compensated by the long term fuel trim function. When the long term function approaches the lean mixture limit (lower limit), the MFI module will interpret the condition as abnormal and the DTC will be recorded.

Substitute value
^ None.

Fault source(s)
^ Contact resistance and oxidation in MAF sensor connector.
^ Faulty MAF sensor.
^ High fuel pressure.
^ EVAP system leakage.
^ Contaminated engine oil.
^ High oil level.
^ Leaking injectors.

Fault symptom(s)
^ May cause high fuel consumption.
^ May cause impaired performance.