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valleybusman
Top Member

USA
798 Posts

Posted - 02/06/2016 :  10:18:30 PM  Show Profile  Send valleybusman an AOL message  Reply with Quote
I have a Allison in a 2011 CE 300 with a VT 365 . Before I go tearing into it . I am getting an electrical fault code on the dash . I checked for codes and none . That was with service maxx . I then pickuped the allison doc . When I try to retrieve codes . Says it cannot connect .Bus will not start or even turn over . Just clicks at the solenoid by the drivers window .I thought NSBU switch . I went to replace that and find there are a couple wire connections I can't disconnect to remove the valve body . One question is do I need a special tool to disconnect those solenoids ? Next question when I look at the listener screen it shows engine and brakes . Does this mean I have no power to the TCM ? One night the driver brought bus back after run . Next morning bus would start but light on trans gauge would flash and it would beep with the electrical fault .The shiftier isn't a keypad

Edited by - valleybusman on 02/06/2016 10:59:57 PM

flint1
Senior Member

Canada
74 Posts

Posted - 02/07/2016 :  9:06:17 PM  Show Profile  Reply with Quote
When I r/r the valve body, I remove the pass thru from the case and remove the body with the internal harness.
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RonF
Top Member

867 Posts

Posted - 02/08/2016 :  04:27:26 AM  Show Profile  Reply with Quote
In my experience when I have had the electical fault code that referred to the fuses or wire connectors in the battery box or the ECM relay.

US Army retired CMBT
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earl1412
Senior Member

101 Posts

Posted - 02/08/2016 :  10:31:24 AM  Show Profile  Reply with Quote
Ron F has it right, there is a total of 3 fuses at the positive battery terminal in battery box, one of them is for the transmission ecu, I've had these blow before, could not turn over/start. Was able to jump the starter relay at the firewall to get vehicle to run, but driving it to the shop, would not shift properly. Found the culprit to be a bad female terminal in the fuse holder.
earl
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valleybusman
Top Member

USA
798 Posts

Posted - 02/08/2016 :  10:59:15 AM  Show Profile  Send valleybusman an AOL message  Reply with Quote
Just got bus to start . I then checked for codes came up with 5 First one was the throttle pos. . I hooked up service maxx and got a 2545 code saying ECM not recieving body controller CAN messages .Shut down no start
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tkorpal
Active Member

28 Posts

Posted - 02/08/2016 :  2:18:08 PM  Show Profile  Reply with Quote
i had this problem on a couple of my ic 300 with the vt365. there is a three wire plug near the starter, the center wire will melt causing a fault to the ecm and a no start. cut out the plug and wire direct. no more problem

Edited by - tkorpal on 02/08/2016 2:22:20 PM
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valleybusman
Top Member

USA
798 Posts

Posted - 02/09/2016 :  07:00:25 AM  Show Profile  Send valleybusman an AOL message  Reply with Quote
I checked all the fuses and connections . All tight and clean . I did find grounds at starter that I was able to tighten . I did find at the relays there was no ground connections to turn them on . There is no power either at the starter relay and the back up had power but no grounds . I tried new relays and nothing changed . Does the neutral switch provide the grounds for these 2 relays to make them work ? If so what else could the NSBU switch also provide .Thanks
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JoeHEB1
Advanced Member

498 Posts

Posted - 02/09/2016 :  08:13:21 AM  Show Profile  Visit JoeHEB1's Homepage  Reply with Quote
Try swapping out TCM with a known good one. I had a similar problem, after checking all my connections and relays I did the ol switcharoo trick and fixed the problem.
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dsalinas1939
Top Member

USA
1316 Posts

Posted - 02/10/2016 :  5:44:57 PM  Show Profile  Reply with Quote
I have had a similar problem with a no start was losing voltage at the nsbu relay turned out to be a bad break not sure if u have breakers or fuse but I have run across a bunch of bad breakers that would get corroded insided due to moister because the side door leaks not sure if that helps but just a thought
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valleybusman
Top Member

USA
798 Posts

Posted - 02/12/2016 :  08:34:44 AM  Show Profile  Send valleybusman an AOL message  Reply with Quote
I ran allison doc .It would not read the transmission . So I took bus out . No speedometer , have to bypass starter relay and won't upshift . Where is the relay that controls all this and the NSBU switch ?
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dsalinas1939
Top Member

USA
1316 Posts

Posted - 02/12/2016 :  12:48:08 PM  Show Profile  Reply with Quote
should be in side panel on the right side of fuse block i beleive its the second from the top
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dsalinas1939
Top Member

USA
1316 Posts

Posted - 02/12/2016 :  12:50:38 PM  Show Profile  Reply with Quote
thats for the NSBU switch i believe its the second from the top might be the top but again i think its second from the top
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mastertech
Advanced Member

274 Posts

Posted - 02/12/2016 :  8:20:33 PM  Show Profile  Visit mastertech's Homepage  Reply with Quote
If the software is not talking to the trans you most likely have a bad power or ground leads. At the allison class they taught us how to run a jumper on the tranny connector to get the bus started and in the shop. Dont drive long with the trans in default because it goes into 3rd gear and will smoke the tranny if you drive it to long. Ill see if I can dig up the schematics. I assume this is the gen 4 trans with the small computer with the pin type cooling fins?
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valleybusman
Top Member

USA
798 Posts

Posted - 02/12/2016 :  9:58:38 PM  Show Profile  Send valleybusman an AOL message  Reply with Quote
Yes it has the cooling pins . That would be fantastic if you could give me that info !!!I am thinking relay .
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valleybusman
Top Member

USA
798 Posts

Posted - 02/12/2016 :  10:00:39 PM  Show Profile  Send valleybusman an AOL message  Reply with Quote
Thanks for the info dsalinus1939 I will check that out too !!!!
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Tb4020
Senior Member

United States
82 Posts

Posted - 02/14/2016 :  04:44:20 AM  Show Profile  Reply with Quote
I think it's more like RonF said but open the loom that contains the ecm power wires from the batt box and look for a green blister those wires have been a problem for harvester since the 3800's went electronic. I've been helping a school till they can hire a new mechanic and have found this on 3 different buses in the last month.
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mastertech
Advanced Member

274 Posts

Posted - 02/17/2016 :  03:24:08 AM  Show Profile  Visit mastertech's Homepage  Reply with Quote
Sorry for the late info . Ignition voltage is on pin 63. Battery power is on pins 70 and 10. Grounds are pins 69 and 9 . If you apply 12 volts to pin 41 it will energize the neutral start relay to get the bus started then the trans will go into 3rd gear or reverse to limp home. As stated load test the powers and grounds to be sure they dont have high resistance from corrosion.
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valleybusman
Top Member

USA
798 Posts

Posted - 02/17/2016 :  08:47:52 AM  Show Profile  Send valleybusman an AOL message  Reply with Quote
Thanks Master tech
I tracked the problem .down . No battery power .The wire to the TCM had the insulation rubbed off and it corroded it's way thru the wire.
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