S/N CAST0299DVD901112 Hello, first time to post. Need some help with this problem . When this machine warms up I get a 636-2 code first then a 190-2 and then 3509-4 and it will set a 157-2 and derate. The engine will miss until it derates, smooth for a minute then will shut down. Logged codes in order 157-2, 636-2, 3509-4, 523611-2, 190-2. I have been told to replace the fuel rail because the only way to get the senso is to buy the rail. This seems to me to be a control voltage problem. I would love see a full schematic on this. Help please !
Could the rail pressure sensor be the problem ?
In the order that they appear the Codes are: - 636-2 - Engine Speed Sensor, signal erratic, itermittent, or incorrect. 190-2 - Ditto above, but recorded in the machine ECM rather than the engine ECM. 3509-4 - Sensor Power Supply #1, voltage above normal. 623611-2 - HP fuel pump pressure too high. 157-2 - Engine Injector Metering Rail #1 Pressure : erratic, intermittent, or incorrect. I would suggest to start diagnosing from the engine speed sensors first. Your list of Codes/Events has the all the indications of a knwn issue on that Kubota engine of an intermittent wiring harness fault. regularly the cause of this issue is a harness which was pulled to tight around a corner, or was zip-tied enough to squash it, when the engine was assembled.
Thank you very much. I went straight to it. The harness was against the exhaust. Cat had put a def filter on this machine two weeks ago, they didn’t tie the harness back in place. Thanks again for your help with this issue !
If you found it that quickly I would buy a lottery ticket if I was in your shoes.............
I agree. Today was a lucking day! I felt strongly that it was a harness issue. The customer had caterpillar out there before me. They told them it need a fuel rail. They didn't tie the harness back up when they changed the def filter. I had ran my hand back there a few times and didn't feel it. It was more the heat effecting the signal than anything. It had not burnt all the way threw yet. Thank you again
TBH if I was the customer I'd be getting some good photographic evidence and going back at the dealer for a replacement harness under warranty if they didn't install sufficient cable ties to it in the last repair.