Allison MD3060 Blank Selector Shifter

Discussion in 'General RVing' started by antranny, Sep 16, 2005.

  1. antranny

    antranny New Member

    Allisonman,
    I am new to this wonderful site, many thanks to you.
    Just purchased two F750's with Cat 3126 Diesel Engines and Allison's MD3060 transmissions. Will refer to the vehicles as Truck1 and Truck2.
    Truck 1. Model Year 2004,Miles 3,600. Problem: Code d1 4215 according to Allison Short to Battery on D Solenoid. Did the test for shorts at the T harness pin 21 Low side driver and pin 1 high side driver, nothing found checked every other wire in the harness to see if shorting with 21 or 1 nothing found. Did also the test at the transmission feed through harness, nothing found, energized the solenoids to check plunger movement, solenoid D seems to sound weaker than the others, however they all had the same resistance of 4,0 ohms at an average sump temperature of 135 to 140 farenheit.
    As usual, when this code is present gears cannot be selected and also sometimes it is not possible to start the engine. It is possible to cancel the code and start the engine and even drive the vehicle sometimes. However, the problem always comes back. What else can I do to solve this problem??

    Truck 2. Model Year 2004. Miles 1,100. Problem: Secondary Shift Selector Blank. Not possible to start the vehicle, not possible to select gears. Since I have two trucks I switched the VIM from Truck1 to 2 no problem found. Switched ECU from Truck 1 to 2 No Problem Found either, all displays work. (did not drive the truck with the transplanted ECU) Switched the SSS Display from truck 1 to 2 no problem display lights up. What I did find is this. On the VIM 18 pin connector the wire to pins P1 and P2 Red, and Black and Yellow wire respectively had no power with ignition switched on. On Truck 1 these two wires are powered to battery voltage with ignition on. Since I do not have a wiring diagram specific to this vehicle it is difficult to trace these two wires to source. Can you help here again.

    Many thanks. And keep up the good work :cool:
     
  2. antranny

    antranny New Member

    Allison MD3060 Blank Selector Shifter

    About one month ago I made this post. During this time I did some research, first, to understand the Allison WTECIII System and finally to repair the problem. I will now for the benefit of the 90 plus people who read the post explain the cause of the problem and the subsequent fix. First there were two different vehicles with two different problems. This fix applies only to the BLANK SELECTOR SHIFTER. I am still working on the transmission with the code d4215 and will update you when completed.

    The Regular Push Button Selector is powered up by the Transmission Electronic Control Unit (ECU) from Terminal 16 of the "S" Black connector to terminal R of the Push Button Connector located at the back of the display. The Push Button Display also receives its sensor power from terminal 3 of the same ECU connector to terminal N. The battery return or ground signal is supplied from terminal 32 of the ECU connector to terminal P. Without power and ground to the noted terminals the display will not illuminate and unfortunately the engine will not start, as this is also your Netural Safety Device.

    Since the Transmission Electronic Control (ECU) is responsible for powering up the PBD my attention was then focused on this unit and its inputs. Fortunately for me I have two trucks and was able to determine the integrity of the ECU by plugging it in and starting the truck (remember you cannot drive the truck with a transplanted ECU). The ECU gets its power on terminals 1 and 16 of the "V" Gray connector. Some ECU's are powered through a 10amp fuse inside of the Vehicle Interface Module (VIM) out on VIM pins R1 and R2 and in on J1 and J2 from the battery, others as in my case are powered through a 10amp fuse direct from the battery. On testing pins 1 and 16 there was no power, battery return was present on pins 17 and 32. The problem was located. NO POWER TO THE ECU means the ECU cannot power up the Neutral Start Relay, the Push Button Display and the Control Module in the Transmission. The harness leading from the 10amp transmission fuse on the battery, is tie strapped to three or four plactic holders with sharp edges. Three of these brackets are on the frame of the vehicle and the fourth on the starter. The constant movement of the engine, caused pulling of the harness between the fixed and moveable points causing the sharp edges to cut into the insulation and subsiquently wire #N92A cutting off the power to terminals 1 and 16 of the ECU. Once this was repaired and installed the truck could then start and drive again.
    If any of you need my notes and my digital pictures on this problem I will be willing to send them to you. Thanks to those who read the post for helping me to solve the problem. The fact that I did not receive a reply inspired me even more to find a solution. I hope it will help you in future. :cool:
     
  3. aspinc

    aspinc New Member

    Allison MD3060 Blank Selector Shifter

    I have the same problem and could use your notes and digital pictures on this problem . could you please send them to tom_smithy@hotmail.com ?
    Many thanks
    Tom
    Found the problem. It was a 10 amp fuse on the trans the wiring harness.
     
  4. Don Page Sr.

    Don Page Sr. New Member

    Allison MD3060 Blank Selector Shifter

    Hi, I too am having power problems and believe the ECU may have a loose wire, would you be so kind as to forward your information to: donandvon@comcast.net /Thanks will post what i find if anything..LOL
    Thanks, Don Sr
     
  5. aspinc

    aspinc New Member

    Allison MD3060 Blank Selector Shifter

    Found the problem. It was a 10 amp fuse on the trans the wiring harness.
    Thanks all
    Tom
     
  6. antranny

    antranny New Member

    Allison MD3060 Blank Selector Shifter

    Hi Don,
    You may want to check like Tom, the Transmission feed fuse located on the battery box or in the VIM (Vehicle Interface Module) some where over the transmission on a cross bar. Also you want to make sure that theECU has constant power on the "V" harness (GRAY in COLOR) on pins 1 and 16, and battery return (ground) on pins 17 and 32. Without power on these wires and ground as well the ECU will not work. I will send you my notes as well as my pictures. Let me know your progress. I am willing to walk you through the diagnosis and repair.

    Antranny
     
  7. tony48

    tony48 New Member

    RE: Allison MD3060 Blank Selector Shifter

    I was given a job on a f 750 that would not start and the shifter was blank. I know that it has a 10 amp fuse and that was good. There was no power to the transmission. To make a long story short, the power wire going from the fuse to the transmission was cut but you could not see it thru the insolation. The wire tie was so tight it cut thru the wire from the vibration
     
  8. wscwilliam

    wscwilliam Junior Member

    I am having the same problem after storing my coach.

    I am having the same problem after storing my coach. Can you send those pictures to please send me the pictures at se7enracer@yahoo.com .

    Thanks, Will
     
  9. LEN

    LEN Senior Member

    Welcome and good luck as the most resent post was 2 years ago and the older was 7 years ago. Now as to your problem check the power to the controls both with ingnition switch on and off.

    LEN
     
  10. jimkmiller49

    jimkmiller49 Junior Member

    antranny,
    That is some really good information. I have the same problem and currently stuck in a rest area along side of the freeway.
    Would you be so kind as to send me the pictures that you taken concerning the location of this 10 amp fuse and where is the VIM.
    I am an aircraft mechanic and pilot, not a motorhome mechanic, so I can use all the help I can get.
    send to: jimkmiller49@yahoo.com
    Thank you.
    Jim
    I have a 1993 38 ft american eagle with no power to the shift panel selector.
     
  11. Marty McLallin

    Marty McLallin New Member

     
    DavidV likes this.
  12. Marty McLallin

    Marty McLallin New Member

    Please send pics and info to me. Having same problem. Thanks, Marty
     

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