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2003 U320 Anybody know where tranny ecu connects to data link

July 17, 2013, 12:42:01 pm

We have no transmission temperature indication on the dash gauge or the Driver Information Center, so we are at Spokane Allison to have them check it out.

The Allison tech cannot "see" any tranny info when he connects to the data link connector.  Their diagnostic program just says there is no connection to the tranny ecu.

Tech thinks there is a wiring issue,  I agreed it was a waste of $$$ to have him chase wiring, so Jim will get to do it in all of his spare time.  Jim called Mark Harvey who said there were three wires from the ecu to the data link.  The wires are connected with a 3-pin connector to the data link; however, he does not know where the connector is physically located.

So, do any of you know where it might be located?  Sure would save Jim some time.

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Re: 2003 U320 Anybody know where tranny ecu connects to data link

Reply #1 – July 17, 2013, 01:34:42 pm

I have a data link up front by my cummins one.  It is an 01 though.

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Re: 2003 U320 Anybody know where tranny ecu connects to data link

Reply #2 – July 17, 2013, 11:36:05 pm

I'm working my way from the front of the coach to the back, so started looking for the place where the ecu data cable connects to the J1587 data bus.  After a couple of hours searching, I found it under the dash.  Connection seems good (the wires are just crimped together). 

Will go to the ecu tomorrow and check the black "S" connector pins. 

If those are good, then I'll check the integrity of the wiring from the ecu to the connection under the dash.

A good opportunity to buy a "chirper".  I've suspected for quite some time that I need one.

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