Odd transmission dash issue

slowlb7

New member
Feb 10, 2014
135
0
0
des Moines iowa
I replaced the neutral safety switch and pigtails. Tried 2 different dashes, but the "D" on the dash doesn't get the square around it like the other gear indicators do when in the gear. The transmission goes into drive and it drives fine, just doesn't show that you're in Drive on the dash. Does the neutral safety switch just tell the TCM what gear you're in, and the TCM tells the dash? Or do the wires split, like a separate wire for each?
 

slowlb7

New member
Feb 10, 2014
135
0
0
des Moines iowa
Any else had this iusse still can't get it fixed and the shops/ dealer want way more then I'm willing to pay when the truck still drive fine
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,729
297
83
Boise, ID, USA
I've seen that before on older gas trucks when the NSBU wasn't aligned properly. I don't know if it can be misaligned on the Allison or not, but might be worth checking into.

Sent from my FlashScan V2
 

KyleC4

Tech
Dec 30, 2016
470
48
28
Bay Area
Honestly I think you need to have someone with a tech 2 look at the data. Only way to be sure all ranges are matching correctly. A nsbu switch can be slightly misadjusted but also a misadjusted trans shift cable can cause a misreading. That's why I think need to have a scan tool hooked up to be certain.