MD300MH Allison No Keypad Power

[rvmechanic]

Last weekend I drove the 02 Discovery home about 175 miles. We have been leaving it all summer on a rv lot.
The next morning I started it to blow the lines and the Trans Warning Light came on so I manually checked the fluid [cold]. I waited until it wamed up to check it by the keypad and noticed I had no power.
I have since contacted Allison and they had me check the battery connections + & -, the [2] fuses at the VIM and stated that 95% of the time it is a Freightliner issue in the wiring [Oil,Rodents, etc]
I contacted Freightliners [Joey 1-800-3854357] and after a long conversation, he forward the Chassis Wiring.
I have since traced 12v, ground power to the keypad but no ign 12v.
Allison will only sell me a schematic [TS2973EN]. Does anyone have any suggestions?
tom

[rmmpe]

As I understand your problem I can only suggest that if it were me and I absolutely knew where the 12-volt input to the control panel was, I'd run a devoted fused wire from the ignition switch (or switched auxilliary power board) directly to the power line of the control pad.

If the problem still persisted I'd start looking at a bad control pad.

[rvmechanic]

As soon as I get the Allison wiring schematic I will give it a try,
Thanks for yoy help

[rvmechanic]

After checking out the wiring diagrams from Freightliner, I removed the TCM and took it to Williams Allison and was informed that it is fried [they brought it to my attention the burnt smell]. I now need to traced the grounds and also look for chewed wires, etc. The shoch to me is that the TCM price alone is $2400. Any suggestions?

[DAN L]

Quote:

Originally Posted by rvmechanic After checking out the wiring diagrams from Freightliner, I removed the TCM and took it to Williams Allison and was informed that it is fried [they brought it to my attention the burnt smell]. I now need to traced the grounds and also look for chewed wires, etc. The shoch to me is that the TCM price alone is $2400. Any suggestions?

your moho is old enough for parts to be in wrecking yards.

[rmmpe]

Failing to find it in a salvage yard (which will likely charge 50% or so of new) if it were me, I'd take the panel to an electronics repair facility to at least see if it can be repaired and get an estimate/quote. Also, as this model is probably obsolete, I'd suspect whatever you get from Allison is a remanufactured/repaired unit.

Do not despair
Send it out for repair
The OEM price can't compare
To a price that is fair.

[st687]

Call John at Transmission Instruments 1-866-439-9779 he can repair your ECM

[94-Newmar]

Quote:

Originally Posted by st687 Call John at Transmission Instruments 1-866-439-9779 he can repair your ECM

I second this motion. We recently purchased a 94 Newmar Kountry Star and its a Cummins 8.3/300hp with an Allison World 3060 trans using a WTEC-II controller - which failed. Sometimes it would power on, sometimes not. If it did power on it only stayed on about 30 seconds or so.

Was able to get a couple of codes out of it, both were 69 xx codes which John at Transmission Instruments told me was the keypad/ECU. We took it out (15 mins) shipped it off overnight to John with a return overnight label in the box, John fixed it and shipped it out the following day, $300.00. All fixed, problem solved.

Allison wanted over 2000.00 since they said we needed to upgrade to a WTEC-III/IV unit.

John rules.

[rvmechanic]

I received the reworked TCU from John at Transmission Instruments and installed it last night. So far everting looks good. I need for the weather to pass before I can re-install the driveshaft and take it for a test drive. Thank all of you for your comments and help.

[st687]

Glad to here you are getting it back together.
Bill W .
Merry Christmas

[rvmechanic]

I just finished a 1500 mile round trip to Norfolk Va and everything worked well with the rebuilt ECU.
Happy New Year to All

[viktorskyler]

Quote:

Originally Posted by rvmechanic As soon as I get the Allison schematic, I will give it a try.

Hi rvmechanic,

I have the identical issue, and my situation is urgent. The five (5) wires going into-and-out of my 'no-power' keypad are:
purple and white,
yellow and teal,
red and blue,
yellow and red,
black.

According to your schematic, which is power, which is ground?

thank you,
viktor
viktorskyler@yahoo.com

[BMsuper]

Victor, I had the same problem. Sent my ECU and Keypad to John at Transmission Instruments in Texas. He charges $300 and fixes it in a day and a half. Had it back withing 8 days with ground shipping from NY. He also has a website. Do Contact Him, He's Good and He's Fast.

Bob F. See my post under "Do Not Shift" BMsuper

[wagonmaster2]

Still trying to learn all about the DPs. What is the ECU and where is it located? What is its purpose? What does it look like? I have a 3000 Allison in a 2004 Freightliner chassis with the Cat C-7 engine.
And there was a reference to a TCU, what is that?

Thanks for any information.

Wagonmaster2
2004 Meridian 36G