MT225s RPM surge

[farmiguy]

As a tech who works on the more technical side of things with LS, if the harness failed or was not preforming like it should 1) weather isn't going to effect the harness functionality, and 2) it would most definitely have issued codes through the CPU and while they may not show up on the dash readout they would still be there, tell them to hook up their evci tool and pull your code history and see what failure is has registered in its history log, those codes may not be active on the dash until the problem occurs and then once its running it could be storing them direct to history, I've had this happen several times, have them look for a codes in the history that have the most occurrences and have them check how often it is occurring, this should allow them to be able to pinpoint what is happening.

Thanks for your reply. The tractor was returned about 3 weeks ago and has been running fine. However it does not mean the problem is corrected as the RPM surge occurs more often at below freezing temperatures. Thus I will have to wait until late November for more accurate results. I hope we have colder weather early this year as the warranty expires in late December. I was told by the dealer that this model (MT225s) has limited diagnostic code features. The idea to replace the harness vs the injector pump was that of an LS tech from Canada, he told my dealer he had seen this problem many times (in freezing conditions) and a new harness was the solve. I understand that the replacement process required a large tear down of the tractor including removing the entire cab.