A50 No Downshift Above 50 MPH

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April 17th, 2023
Lennydmaxguy

A50 No Downshift Above 50 MPH

Hi guys, looking for some help with this truck. It's a 2013 LML that had a tune on already, but the owner wanted me to retune it. I got it running like he wants, but now the truck won't downshift out of 6th gear above about 50 or so. I thought, no biggie, I'll tweak the shift tables. Wrong. :doh2: As far as I can tell, none of the downshift speed tables make the slightest difference.
I did try flashing the ECM back to stock, and it would downshift up to about 60 or so, but above that it's the same.
The tune on the truck originally did NOT have this problem. What am I doing wrong?
April 17th, 2023
Lennydmaxguy

One detail I forgot to add. The tune in the ecm was a 2011 os. Since the tis2web site is down, I wasn't able to find out what the correct tune would be in a 2013 os, so I used a stock tune that matched all the segments of the tune in the ecm as my base.
April 23rd, 2023
killerbee

Quote:

Originally Posted by Lennydmaxguy

Hi guys, looking for some help with this truck. It's a 2013 LML that had a tune on already, but the owner wanted me to retune it. I got it running like he wants, but now the truck won't downshift out of 6th gear above about 50 or so. I thought, no biggie, I'll tweak the shift tables. Wrong. :doh2: As far as I can tell, none of the downshift speed tables make the slightest difference.
I did try flashing the ECM back to stock, and it would downshift up to about 60 or so, but above that it's the same.
The tune on the truck originally did NOT have this problem. What am I doing wrong?

The 2013 did not come with an A50 stock, if I recall. The OS ends in 711
April 23rd, 2023
Lennydmaxguy

1 Attachment(s)

Quote:

Originally Posted by killerbee

The 2013 did not come with an A50 stock, if I recall. The OS ends in 711

That's the OS I have. Efilive calls it an A50. This is the tune that I read out. It may or may not be the correct one, but it worked ok before.

Attachment 24411
April 23rd, 2023
killerbee

Quote:

Originally Posted by Lennydmaxguy

That's the OS I have. Efilive calls it an A50. This is the tune that I read out. It may or may not be the correct one, but it worked ok before.

Attachment 24411

OK, so flash it back into the original T14. Or am I confused?
April 23rd, 2023
Lennydmaxguy

Quote:

Originally Posted by killerbee

OK, so flash it back into the original T14. Or am I confused?

Possibly. :)

I only have one TCM, the one in the truck, and that's the file that was in it. Maybe it was already tuned as well as the ECM.
April 24th, 2023
killerbee

You are trying to solve a downshift issue, that is possibly created when you used the "wrong" OS. So I am simply suggesting the most obvious and simplest solution, Occam's razor...put the correct OS back in the TCM.