Medium and Heavy Trucks
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Hi, tell me what the code is if you can. Preheater errors can be the fuse, relay, wiring,ecu, or cracked preheater. Does the code come on as soon as you start the machine? Are any fuses blown in the cab or the large battery ones in the batter box? Have you used a ohm meter and touched the lug on the preheater and the other lead to ground and got a reading about 1 ohm? The preheaters do fail but best to make some simple checks before throwing the parts at it. Thanks for asking for me, let me know.
hello, thanks for that info. Okay that code is for a communication issue with the ecu. Disregard the preheater all together for this code. Seeing this code I would normally take my break out box and check the engine ecu for power and grounds. I assume you do not have this ability so a couple things to look at would be the relay for the ecu. Above the battery box there is a cover in front of the fuel tank. four bolts 18mm socket. remove and under that is another box that holds the relays, remove cover 10mm socket. Replace RE3 and RE4 with new 24 volt relays, they are the data and communication for the engine. Next remove the Iecu by your knees when sitting in the machine. It should be a digital one with 4 buttons on the bottom. If so remove the back cover that has 4 torx screws. inspect the circuit board plug at the bottom of ecu for corrosion. Third is to unplug the connectors behind the seat one by one looking for corrosion and the same goes for the plugs under the relay box. Also the auto manual switch by your elbows, look for broken or chaffed wires on that again checking all fuses first. let me know serial but this should point you in the right direction. does the machine run?