Anyone had this happen before?

CCLB06

Member
Jan 4, 2020
37
1
8
Ohio
Having a weird issue with the shift indicator light, it only highlights Park, Neutral and Manual. I also don’t have reverse lights either and sometimes the DIC will say “Range shift inhibited”. I also am getting a P0708 code for Transmission range sensor circuit high.

I’ve replaced the TCM with a new one and the issue is still there. I think the internal mode switch needs replaced.

I posted a link to my YouTube video below showing the issue I am having.



Source: https://youtu.be/mxlA7GJZ49E
 

MAXX IT OUT

<<<IT WORKS
Mar 1, 2013
1,774
34
48
Des Moines, Iowa
Have the checked the wiring that goes to the NSBU? I have had a issue with my reverse lights and it ended up be a wire that burnt or corroded out that went to the NSBU since the was power was actually switched on the transmission for the reverse lights. I don't know of the wiring for the 6 speeds are the same as the 5 speeds, but its worth a quick check.
 

CCLB06

Member
Jan 4, 2020
37
1
8
Ohio
Have the checked the wiring that goes to the NSBU? I have had a issue with my reverse lights and it ended up be a wire that burnt or corroded out that went to the NSBU since the was power was actually switched on the transmission for the reverse lights. I don't know of the wiring for the 6 speeds are the same as the 5 speeds, but its worth a quick check.

I have checked all the wiring, didn’t notice any Damaged or corroded wires. I’ll be testing the voltage on the connection for the pass through harness this weekend. I’m confident that it’s the Internal mode switch though.
 

CCLB06

Member
Jan 4, 2020
37
1
8
Ohio
*UPDATE*
well I was getting ready to head to the store to get transmission fluid, had already purchased everything online. While I was waiting for the truck to warm up I decide to get my tools ready and prep for dropping the transmission pan to change the fluid and replace the IMS ( internal mode switch ) I crawled under the truck to make sure I had a socket big enough to fit over the pass through harness connector so I could remove the valve body. After plugging the connector back in I jump in my truck put it in reverse and “BAM” everything is working like normal, shift indicator light, lights up PRNDM1, I’ve got reverse lights and all that jazz. Not sure what the hell has been going on but it’s been working fine since. Sadly enough it seems I wasted money on a new TCM 😩
 

CCLB06

Member
Jan 4, 2020
37
1
8
Ohio
Any signs of fluid/gunk in the connector?

There was very little trans fluid in the connector area. I checked this once before cleaned it out with air and it did NOT fix the problem. This go around I didn’t clean the fluid out, no issues so far, So I’m dumb founded what the problem actually was.