Wierd Allison 740 issue...I'm defering to the experst here!

[Scott & Heather]

Jeff,

definitely not trying to be a nitpick...so take this with half of a quarter of a grain of salt, but i think the abbreviation is indeed "ATEC" not ATEK. Your sig also spells it ATEK which if someone were to google, or try to search in a manual, wouldn't come up with the results they were looking for. Allison Transmission Electronic Control I think is what it stands for. Anyway, I agree completely that if you let someone tinker with your ATEC trans, you're asking for trouble. When I get home I will spend some time trying to find said switches. I don't have key ignition but rather just an ignition switch so I'll experiment...

[luvrbus]

Kontrol or control   but is ATEC,I think he just has a ground he needs to chase down   

[jackhanow]

the manual I have has the codes and diagrams, I'm just hanging out, if he gives us a number, we can go from there. It also gives the power and ground numbers. It's a newer version so I think it's got the correct info.

[luvrbus]

I found how to retrieve the codes for him

Start the engine  

Shift the gears and then place in neutral

Hold the test switch on with the engine at idle

The important Codes will flash

Now all he needs to do is find the test switch   

To Clear the codes

Stop engine

Turn the test switch on

Start the engine

Shift from neutral to reverse back to neutral and stop the engine the codes should be deleted  

[rgrimard]

Wow guys this is an awesome ..... great...effort by all of of you. I like the above gentleman do not have a key...just a master on button and an engine start. as soon as we figure out where the test switch is I'll be able to clearcomputer. The transmission goes smoothly through all the gears now that the fluid and filter has been changed and drives nicely. However the light is still on. Disconnected that battery completely 12 and 24....left it off for a few minutes but the check trans light remains illuminated. Where is this switch seems to be the mystery. Perhaps I'll call Mci and see if they would be so kind as to tell me. Thanks again guys . I'll let you know if I find anything. In the mean time keep the ideas coming.
Regards
Ray

[solardude]

Scott, Thanks for the correction, I have made the adjustments.

As for the code clearing procedure, I read the same thing Luverbus has specified, however on my transmission control the procedure I specified in my first post is the one that works in my case. There must be several different procedures. Dang Engineers.

rgrimard

I don't know how long you would need to disconnect power from the TCU, to "clear codes" but there is a fuse, again on MY bus in the battery bay that you should be able to pull to disconnect power from the TCU to attempt to clear codes. I would think overnight would work.
I don't think you will achieve much using that to clear codes. Again with mine, the codes come back within 20 min; best to find the correct procedure for your bus configuration.

Let us know how this turns out, I'm always interested in hearing how these transmission issues get resolved.

Good Luck!

[rgrimard]

Just pulled the fuses...my by also had fuses in the battery box. I'll check it tomorrow and let you guys know what I found.
Ray

[jackhanow]

So we gave you three places to look, per manual, did you look there, oil and filter is seldom the problem.

[luvrbus]

He needs to be sure what transmission he has in the bus and tell us

[rgrimard]

Ok guys this is what I've found. First of all I HAVE located the ATEC module and test switch;it was in the rear luggage compartment (driver's) side on the tunnel ...4 zeus fasteners and it swung down. Thank you very much for sending me in this direction (I would never have located it without your help).. OK so I followed all of the procedural steps you all sent me but unfortunately to no avail. I also found the port where one must plug in a Pro/Link  to the right of the drivers chair on the ground...also with the expert directions you all provided.

The test switch (at least on my bus) is a momentary switch located under a switch safety latch which I toggled and nothing seemed to change with the "check Trans" light after I powered it up and down (following the gear cycling steps you sent me) I even tried to hear (or see) if the check trans relay energized  when I hit the switch...nothing. The check trans light still glows brightly (defiantly).So...I followed the directions from iluvrbus and located wires 222,215 and 216A. Wire 222 has  great continuity to ground (as expected) however wire 215 (was supposed to be grounded and according to the schematic goes to the check trans relay) came up as an open...no connection to ground. If this is a great possibility...then what should I do? Should I splice in a ground connection? Trace it back..uggh? wire 216A also came up as open (not grounded). Only suspected reading was wire 215. 

FWIW the bus fires up without any beeps or blinks and goes in and out of the selected gears back and forth to neutral with out any issues. What do you guys think?

Ray

[jackhanow]

So my book says 202, 223a +12volt. 203 continuous 12v powered memory, 208, 209 battery ground, 201 chassis ground ,210a ground. 215 is scanner read wire not ground. You must hold the switch to Trans until it finishes flashing the codes. Turn on main switch and hold check switch to Trans and count the blinks. Check battery cables. Make sure they are tight.

[luvrbus]

Is the "check trans" the only light staying on ? if so it's probably a bad check trans relay or a bad engine oil switch wire 215 is a mandatory interlock to the oil pressure switch on the engine

[Scott & Heather]

Hmmmm, and the thot plickens.

Are you referring to the "check Trans" light on the dash? Truth is, on my C3, that silly light goes on and off at will due to a little short somewhere in my left armrest panel (the one with the dash light dimmers). I can move that panel around or bang on it and the "check Trans" light will shut off. Me thinks that if the Trans is really malfunctioning it will not let you go into gear and I think it even beeps at you from what I remember when mine was giving me fits. So if it's shifting fine, your fluid level is good and the fluid looks healthy, I would assume your Trans is ok and look to a dash wiring short or bad connection as is the case with my C3.


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[luvrbus]

Check Trans is not a code the codes are flashed on the "Do Not Shift", here is what the books says since yours is working good

Check Trans light only

Vehicle drives normally

faulty Check Trans relay
faulty cab harness wiring
faulty ECU
faulty engine oil pressure switch
engine oil pressure low

when a ECU gets what called a cat eye the light will stay on and most folks don't replace the ECU just for that lol I have seen a lot of duck tape over the light.

A ? does the transmission have a retarder

[rgrimard]

iluvrbus
Yes the Check Trans light is the only one that stays on. Perhaps it is the check trans relay. I might have another one...I will put it in and check it. Thanks again
Ray