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Low Trac Light when leaving reverse and some other transmission questions...

HighCaliber

New member
I have only been driving my (new to me) GTP for a month or so and I have to say I love every second of it. I clocked about 2,000 miles this month mostly in longer distance jaunts to work, but even around town this thing is awesome.

However, there are a couple concerns I hope you guys/gals can shed light on. I will start with my main issue then I will digress.

1) When backing out of my driveway/parking stall and putting the transmission selector from Reverse into Drive the "LOW TRAC" lights up on the DIC. I don't know if I am crazy but it seems to also hum a little bit like a kind of a vibration noise? I don't have a clue why it does this and it does not happen every time I reverse. The light shuts off within a second or two and the car seemingly runs fine.

2) How much play does your transmission have when it is put into Park? Also when put in Reverse from Park? I feel like when I park the car even without it being on any incline the car moves a solid 3"-4" forward or backwards before before the transmission pawl stops it from moving. Therefore I have been setting the ebrake on all surfaces because of this. I have always done this on hills because I drove manual for so many years.

3) This is probably directly connected to #2 but how much does your GP move forward or backwards when you put it into reverse or drive from park? Mine sometimes jumps abruptly like a "hard" shift...but then most of the time it does not.

I know my paragraphs seem vague and cryptic but I am wondering if I am going crazy. I am coming from driving a new GMC Sierra 1500 that was smooth as butter in the engine/tranny department. I understand this car is 10 years old so bear with me and my concerns. I am hoping I just need mounts and/or bushings to tighten things up but don't know where to start :).
 
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1) I drive a GT so no idea on this.

2) I have maybe 2-3" movement after using park only, depending on the incline. It doesn't have to be a huge hill to make the car move a little, and since I just got my transmission totally rebuilt I'm going to say this is normal.

3) My car sometimes did this when coming out of park. It's usually if not always caused by parking with just Park on a incline, even a slight one, because of the pressure exerted on the pawl holding the car in place. It is possible to even "lock" the shifter in park from that pressure alone if the incline is steep enough and then you won't be able to move the lever at all. From what I understand the correct procedure is ebrake on, THEN shift to park. That's what I almost always do on all surfaces and I really haven't noticed this happening since.
 
1) I drive a GT so no idea on this.

2) I have maybe 2-3" movement after using park only, depending on the incline. It doesn't have to be a huge hill to make the car move a little, and since I just got my transmission totally rebuilt I'm going to say this is normal.

3) My car sometimes did this when coming out of park. It's usually if not always caused by parking with just Park on a incline, even a slight one, because of the pressure exerted on the pawl holding the car in place. It is possible to even "lock" the shifter in park from that pressure alone if the incline is steep enough and then you won't be able to move the lever at all. From what I understand the correct procedure is ebrake on, THEN shift to park. That's what I almost always do on all surfaces and I really haven't noticed this happening since.

Awesome reply!!!

1) Cool
2) That's good to know...thank you.
3) I always ebrake then park so thanks again.

Thanks for your time dude.

Can anyone answer#1?????
 
Last night leaving work...the LOW TRAC light came on as I was pulling out of a stall and I gave it gas to see what would happen and it definitely makes an almost ABS sound/feeling and was underpowered. Then the light shut off and I was on my way as usual. Things that make you go hmmmmm.
 
LOW TRAC detected (when traction is good) is usually due to wheel speed sensors inside the wheel bearings going bad or having a loose connection.
I have this same problem due to my left front sensor cabling going bad.

I have had some success putting dielectric grease on the metal connector parts to give it a solid signal connection.
but also sometimes if I just jiggle the wires leading into the wheel bearing it makes the problem go away for a while.

The fix for me and you will likely be to replace the problem wheel bearing (w/ speed sensor)
if you scan for ABS codes you will likely see a failure on 1 or more of the speed sensors.
there is 1 per wheel of course.

 
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