Troublshooting-Oxygen Sensor - Kohler command pro ECH749 Service Manual

Troublshooting-Oxygen Sensor (O
Condition
Low voltage output.
High voltage output.
Open circuit, no activity from sensor.
Slow time response.
24 690 01 Rev. K
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Possible Cause
Shorted sensor or sensor circuit.
Shorted lead wire.
Wiring shorted to ground.
Contamination of air reference.
Air leak at sensor or gasket, sensor
upper shield damage.
Silica poisoning.
Contaminated gasoline.
Engine problem; misfi re.
Excessive rich air/fuel ratio.
Wiring shorted to voltage.
Broken element.
Sensor dropped.
Hard blow to engine or exhaust
system.
Defective sensor.
Thermal shock.
Open heater circuit.
Improper handling.
Carbon deposits.
Improper fueling.
Incorrect or contaminated fuel.
Excessive engine oil consumption
causing exhaust contamination or
other exhaust side contamination.
Heater circuit open/shorted or out of
specifi cation.
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Conclusion
Replace sensor or repair wiring.
Remove source of external
contamination, protect air reference
area.
Use recommended torque at
installation, replace gasket or sensor.
Revise application exhaust.
Shield sensor from damage.
Replace sensor.
Use high quality fuel.
Correct cause of misfi re.
Check for high fuel pressure.
Leaking injector.
Liquid fuel in vent line.
Repair wiring.
Replace sensor.
Replace sensor.
Correct fueling.
Use high quality fuel.
Correct engine condition.
Repair short in harness wires, replace
sensor.
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