34
UnclassifiedGeneral
What This Code Means
System operates 'closed loop'; No appreciable performance loss as long as the temporary adaptation can provide sufficient compensation
Possible Causes
- •Base engine problem (rings, valves)
- •Blocked or restricted fuel return circuit to tank
- •Combustion air system problem (dirty/restricted air cleaner, intake leak, throttle bores)
- •ECU-to-harness connection problem
- •Exhaust system leak
- •Fuel in the crankcase oil
- •Fuel system problem (fuel type/quality, injector, fuel pump, fuel pressure)
- •Ignition system problem (spark plug, plug wire, ignition coil)
- •Oxygen sensor connector or wiring problem
- •Oxygen sensor contaminated or damaged
- •Pin circuit wiring or connectors (Pin 10 for 35 Pin MA 1.7 Metal-Cased ECU, Pin 11 for 24 Pin MSE 1.0 Plastic-Cased ECU, Pin 20 for 32 Pin MSE 1.1 Plastic-Cased ECU)
- •Poor ground path
- •Uncleared ECU fault codes after problem correction
Suggested Actions
- 1Disconnect the negative (-) battery cable from battery terminal, or remove the main fuse for the ECU for approximately 1 minute
- 2Reconnect the cable and tighten securely, or reinstall the main fuse
- 3Start the engine and allow it to run for several minutes (10-15 minutes of running may be required for codes 31, 32, 33, and 34 to reappear) to verify the MIL remains off
ASK RUDY ABOUT THIS FAULT
Get a diagnosis walkthrough for 34 on your specific KOHLER CO. unit — cited to the OEM manual, not a forum guess.
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