225
UnclassifiedGeneral
What This Code Means
DST displays HO2S voltage fixed below 0.35 after 2 minutes of run time; Lean exhaust condition at light load; False lean condition during light load conditions
Possible Causes
- •Closed Loop multiplier exceeds the limits of normal operation
- •Exhaust leak allowing outside air past O2 sensor
- •Faulty ECM grounds
- •Faulty HO2S sensor
- •Fuel system operating out of specification
- •Large vacuum leaks
- •Multiplier cannot correctly modify the fuel flow within its limits
- •Oxygen sensor wires mispositioned and contacting the exhaust
- •Short to ground between harness and sensor or on sensor harness
Suggested Actions
- 1Check and adjust fuel system according to PSI guidelines
- 2Check for short to ground between harness and sensor and on sensor harness
- 3If any other DTCs are present, diagnose those first
- 4If fuel system is operating to specification, replace the HO2S sensor with a known good part and retest
- 5Verify ECM grounds are good engine or battery grounds
- 6Warm engine to normal operating temperature by idling for a minimum of 2 minutes
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