Goes to "DO NOT SHIFT" instead of upshift

[ewalton9]

2000 Discovery,275 Cummins,Allison 6-speed. Trans shifts into drive but when rpm reaches level to upshift, digital display changes to 1, "Do Not Shift" warning light comes on and trans will not shift. Fluid level is OK and digital display only shows 07, not up to temp. No trans service, fluid change,etc in at least 60000 miles. I live some distance from a shop certified to go into the trans, but could probably get the filters and fluids changed locally. Does it sound likr the filters might be the problem? Thanks!

[Mike Canter]

If there was a CheDo Not Shift light then there was a fault code stored. . So with the motor running and the tranny in neutral push both the UP and DOWN shift arrows at the same time on ther tranny shift panel. If it has a Lever vice pushbutton channel then push the MODE button twice. This first push is going to be the Check Fluid Level and your transmission will be too cold so you will get a fault. Now push the two arrows again at the same time and you will be in the Diagnostic Mode and will probably have a fault code. Write it down. Now if the MODE red LED is on means there are more fault codes so push the MODE button to see them. A fault code will look like d,1,1,3,1,2. Each number will appear for about one second so you will first see a "d" the a "1" then a "1" then a "3" then a "1" then a "2". Then it will repeat itself. Once you have wriiten that all down then push the MODE button to read the next code if any. You can clear the codes by holding the MODE button down for more than three seconds. Post your codes here when you get them

[ewalton9]

I followed your instructions with the following results:

1.first push of both arrows: d 07 not up to temp

2.second push: d1 2, 5, 1, 1

3. push mode: d2

4. push mode: d3 etc. on subsequent mode pushes

5. hold mode, exit, return to N

Thank you for sharing your knowledge and experience.

Eddie Walton--98 Discovery

[Mike Canter]

Which tranny do you have? Do you have the manual with the codes? I am guess you have a 3000 because you pushed buttons. If so it says it is the output of the Speed Sensor that is bad. States to check fluid level, check speed sensor cable for cleaness and tightness, check ECU cables for cleaness and tightness. You can get spray contact cleaner from Radio Shack and pull off those cables and spray both halves and connect them again and see how it runs then. If not the speed sensor maybe starting to fail.

[Pusherman]

Quote:

Originally Posted by ewalton9 2000 Discovery,275 Cummins,Allison 6-speed. Trans shifts into drive but when rpm reaches level to upshift, digital display changes to 1, "Do Not Shift" warning light comes on and trans will not shift. Fluid level is OK and digital display only shows 07, not up to temp. No trans service, fluid change,etc in at least 60000 miles. I live some distance from a shop certified to go into the trans, but could probably get the filters and fluids changed locally. Does it sound likr the filters might be the problem? Thanks!

It's (relatively) cheap insurance to have the fluid and filters changed. Allison recommends 3 years for filters and 4 years for fluid, irregardless of mileage if it's synthetic. 12/24 mos. for dino oil depending on which tranny you have.

It's also (relatively) cheap insurance to have the codes read at an Allison approved shop to figure out what's really going on.

[Mike Canter]

Why do you have to take it into a shop to read the codes if you can read the same ones from the shift panel? The shop will read the same codes and look it up in the same code listing and check the same thing and charge you for it. It sure is easier and cheaper and more exciting to have a go at it yourself first. So many RVers on this forum have fixed things themselves

[ewalton9]

Now that you mention the Speed Sensor, I remember that the speedometer never moved while I ran in 1st gear. I went about a mile @ 1500-2500 rpm and the speedo never moved (did this three times).

Also would appreciate any guidance in identifying the components you mentioned.

The more you tell me, the more this all makes sense!

Thanks again for your help.

Eddie

[Mike Canter]

If you look at the end of the tranny that points to the front of the MH the speed sensor is located at the 3 o'clock position from the driveshaft about 3-4" from the driveshaft. There should be a wire and plug on it. Pull the plug off and check all and spray with contact cleaner. If that don't fix it then maybe a new sensor.

[Perry White]

This help?

[ewalton9]

I cleaned, sprayed, re-plugged and prayed per your directions.

GUESS WHAT!! It shifts like new and I'm a happy and grateful camper.

On the lowest point of the trans, a wire broke as soon as I touched it. I put on a new terminal, cleaned & re-attached. I removed, cleaned, & re-plugged all the other plugs I could find -- including the speed control connection you directed me to.

As soon as I started my test drive, I saw the speedo move and was immediately hopeful. Sure enough, when I got up to speed it shifted and continued thru its progression. I slowed using the Jake, stopped, re-started a few times and it seems to be back to normal.

Thanks again for sharing your knowledge & experience. Eddie

[KIX]

Good job Mike Canter AND OP

[Mike Canter]

I am glad everything worked out for you. I wish it was always that simple. Allison has very good diagnostics.

[Perry White]

I wish I'd have that kind of luck. Good going.