Allison HT 748 Atec Parts Help

[NeoplanAN440]

ok

problem will be if i get it right,
that things like high idle or maybe kneel circuits wont set a code??!!
as the ecu wont know that i didnt switch it on and i maybe still have a problem in these!

a high tps count should be shown as code ??

i didnt do anything different on the last testdrive,only master on and off
and i get different situations but no code or warning light as for now

[Sean]

... things like high idle or maybe kneel circuits wont set a code??!!
as the ecu wont know that i didnt switch it on and i maybe still have a problem in these!

a high tps count should be shown as code ??

No, none of these things is considered to be a problem or failure within the transmission, which is what codes are for.  They are "normal" operator-controlled (usually) events.  High TPS count could just mean you have your foot on the throttle -- that's not a "failure," per se, but the tranny still does not want you to shift into gear with the revs up above idle.

The CEC-1 book that I mentioned will have wiring diagrams for all the tranny inputs, along with wire numbers.  This should help you trace things out, such as the interlock for the kneeling circuit.  Also, the 748 ideally mates to an electronically controlled engine; however, it sounds like you have a mechanical.  So there are senders on the mechanical side that might be touchy, or have loose wires, etc., such as the throttle position sensor (on an electronic engine, the TPS is just a data link between the two control units, so an actual position sensor problem would show symptoms on both the engine and the tranny).

-Sean
http://OurOdyssey.BlogSpot.com

[NeoplanAN440]

thanks again!!!

yes i have a mechanical engine.it has an tps sensor added just for the atec.
from what i found my bus came with a 740 transmission and telma retarder.
before i got it lactma installed a rebuild engine and switched over to a 748.
thats the reason i found a lot of wiring issues and changed circuits i guess!

it looks like i  have to wait till i got the book,as this will maybe getting more fun then expected.
i just build a leveling system where i can override the level valves and select air pressure on each bag.
i just kept the kneeling circuit,because i liked it for loading and unloading before and after our trips.
when the book arrives,i think i can avoid lots of problems by taking out the kneeling and the rest of the door safety circuits.i always kept the front doors wiring in,as i was playing with a remote air door.since i build a single piece front door with an armrest for my wife (more used as a footrest)
our cats have shown us,that they can even outsmart us,by sitting on the door armrest.just waiting for us to open the door to get a peek of the outside.as if its looking different then trough the windshield.
so i stopped the idea with the remote,to have them save inside.

happy bussing

thanks for the help