Data link testing - Service Bulletin 2017

[ewo1]

Here is a doc I found over at the Carolina Thomas Bus web page.

It explains in real simple terms on how to test your data link.

While this doc addresses Thomas busses I feel that it should cover most if not all school busses.

What is a data link?

Why do i need to know this stuff?

When you break down, and you will, knowledge will get you moving forward again, or your credit card will!

[cadillackid]

good read.. this doc is talking about J1939 data link testing...


it is applicable to IH 3800/FE/RE, freightliner, thomas C2, bluebird flat nose with electronic engines....


if your bus is 1998 or newer and has an electronic transmission and engine.. it has a datalink..



MD3060,B300R, allison 1000, allison 2000 series (2100,2200,2500PTS etc)..


theres a J1939 datalink... J1939 is pretty robust but like anything else.. edge.. wire harness chaffing, water intrusion into connectors, etc can break the datalink...



Nobody wants 'Cat eyes' on their allison 3000 shifters!! or the dreaded "shift inhibit" / Check trans" lights

[ewo1]

Here is another service tip doc from the iKNOW knowledge database, doc # MC-10117249 (11 pages).

This doc appears to be for 2013+ model vehicles.


This doc talks about something that I am hearing for the very first time...

1. First, the drivetrain J1939 data link, J1939 body builder data link, and J1939 engine data link are three completely separate data links.

2. They work the same way, but they are not connected.

3. The troubleshooting below is geared towards the drive train J1939 data link, but the same principles apply to the body builder and engine data
link.

Something I haven't found anywhere else but it is here, a chart that shows the pin positions for the datalink wires across a whole bunch of TCM that are found on many different engines & manufacturers.
I don't know if you will find this anywhere else !!


Download, read and save....

You never know when the strange electrical gremlins are gonna appear!