Code 25 - Air-Fuel Ratio Lean Malfunction

Data Trouble Code No. 25 - Air-Fuel Ratio, Lean Malfunction

Detecting Condition
Main Oxygen Sensor voltage is 0.45 volts or less (lean) for 90 seconds under the following conditions (2 trip detection);
- Engine coolant temperature 60°C (140°F) or more.
- Engine speed 1,500 rpm or more.
or
Engine speed varies by more than 15 rpm over the preceding crankshaft position during a period of 50 seconds or more under the following conditions (2 trip detection);
- Engine speed idling.
- Engine coolant temperature 60°C (140°F) or more.

Trouble Area
- Open or short in Main Oxygen Sensor circuit.
- Main Oxygen Sensor.
- Ignition system.
- Engine Control Module.
or
- Open or short in Injector circuit.
- Fuel line pressure (leak or blockage).
- Mechanical system malfunction (timing belt skipped).
- Ignition system
- Compression pressure.
- Air leakage.
- Engine Control Module.

Malfunction Indicator Lamp
Normal Mode ON
Test Mode ON