Kohler Command Pro 28 w/Bosch EFI Throwing 34 & 31 Code after runniig 30-45 minutes
I have a Kohler Command Pro 28 w/Bosch EFI, Spec No. PS-CV745-0004, S/N 3300602011 on a Gravely Promaster 260Z frame. It runs and cuts great for 30-45 minutes and then I get an MIL light. It goes back off after a minute or two then returns to stay on. Continued use results in the engine bogging down and will die if under a load. Reading the flash codes from ECU I get a 34 and 31 (in that order). If I let the unit sit for an hour or so it starts back up fine and operates normally with no MIL light for another 30 minutes or so. The Bosch ECU numbers are P/N 24 584 29, S/N 5000696 and is a 32 pin MSE 1.1 version.
I used the troubleshooting guides in the maintenance manual and realize these code have to do with the TPS sensor and Oxygen Sensor. They both check out OK. When the engine is acting up as described above I can see that the throttle is being held wide open by the governor. I have read a couple of posts concerning similar issues but didn't find anyone that came back to report a good fix for them. When I checked the readings on the TPS sensor I get 945 ohms when full closed and as I rotate the throttle towards full open the reading increases till I get to 1996 ohms but the throttle is not at WOT yet and continuing on towards WOT the reading goes to open (no continuity). Thought that wasn't right so I purchased a new TPS sensor from Kohler. In checking out the new TPS sensor (I haven't installed it) I find that the readings are exactly the same as original TPS above (that is still installed) so I don't think the installed one is causing the problem even though the 34 code is being reported.
Concerning the Oxygen sensor, I removed and reinstalled it after cleaning the tip (it wasn't carbonned up and fins were open) and it is putting out the correct voltages when it reaches operating temperature. So again I don't feel that is causing the problem even though the 31 code is being reported.
I haven't done a TPS Initialization Procedure on the system because of the way the unit starts back up and operates for another 30 minutes or so after sitting. I would think that if ECU has lost the learned setting from the installed TPS sensor it would not start back up and operate fine like it does.
I appreciate anyone's input on this issue because the Kohler dealer in my area say they don't know much about the Bosch EFI systems since Kohler stopped using them 3-4 years ago. Of course they want me to switch it to the Delphi EFI...
Thanks.... in advance....
I have a Kohler Command Pro 28 w/Bosch EFI, Spec No. PS-CV745-0004, S/N 3300602011 on a Gravely Promaster 260Z frame. It runs and cuts great for 30-45 minutes and then I get an MIL light. It goes back off after a minute or two then returns to stay on. Continued use results in the engine bogging down and will die if under a load. Reading the flash codes from ECU I get a 34 and 31 (in that order). If I let the unit sit for an hour or so it starts back up fine and operates normally with no MIL light for another 30 minutes or so. The Bosch ECU numbers are P/N 24 584 29, S/N 5000696 and is a 32 pin MSE 1.1 version.
I used the troubleshooting guides in the maintenance manual and realize these code have to do with the TPS sensor and Oxygen Sensor. They both check out OK. When the engine is acting up as described above I can see that the throttle is being held wide open by the governor. I have read a couple of posts concerning similar issues but didn't find anyone that came back to report a good fix for them. When I checked the readings on the TPS sensor I get 945 ohms when full closed and as I rotate the throttle towards full open the reading increases till I get to 1996 ohms but the throttle is not at WOT yet and continuing on towards WOT the reading goes to open (no continuity). Thought that wasn't right so I purchased a new TPS sensor from Kohler. In checking out the new TPS sensor (I haven't installed it) I find that the readings are exactly the same as original TPS above (that is still installed) so I don't think the installed one is causing the problem even though the 34 code is being reported.
Concerning the Oxygen sensor, I removed and reinstalled it after cleaning the tip (it wasn't carbonned up and fins were open) and it is putting out the correct voltages when it reaches operating temperature. So again I don't feel that is causing the problem even though the 31 code is being reported.
I haven't done a TPS Initialization Procedure on the system because of the way the unit starts back up and operates for another 30 minutes or so after sitting. I would think that if ECU has lost the learned setting from the installed TPS sensor it would not start back up and operate fine like it does.
I appreciate anyone's input on this issue because the Kohler dealer in my area say they don't know much about the Bosch EFI systems since Kohler stopped using them 3-4 years ago. Of course they want me to switch it to the Delphi EFI...
Thanks.... in advance....