TXjeepTJ

iTrader: (8)

Transmission slams into gear when going from park to drive. Which tables to adjust?

Idle is at 650, dropping the idle doesn’t solve the problem

this is on an LS3 that is running a 4L60E, so I had to take an E38 from a 2008 Yukon XL and segment swap in the 60E. So I’m thinking something Just needs to be tweaked in some table, maybe to reduce line pressure?

warriorpluto

iTrader: (2)

When i had hptuners i remember a setting called garage shift. You may have to adjust that to soften it up

ssdungeon

iTrader: (24)

Does it do it when cruising at low speeds in a parking lot 1st to 2nd? If it does are you having any MAF codes?

TXjeepTJ

iTrader: (8)

Yup, it was throwing a P0101. Something is going on with the MAF sensor, as it's not giving any reading to the computer.. another issue..

Anyways, I set P0101 to "no error report" and it fixed the issue. So I just need to figure out whats going on w/ the MAF that it's not sending any signal. I believe setting P0101 to "no error report" isn't a good thing lol

Kawabuggy

iTrader: (1)

As you have figured out-the MAF is tied directly to transmission line pressure. If you have problems with the MAF signal, the PCM will sometimes spike the trans line pressure to max in an attempt to save the transmission from slipping clutches, and damaging the transmission inside.This is why you feel the harsh engagements. So yes, resolve your MAF issue before you drive it anymore. Though you have solved the harsh engagements, you may now be driving the car with low line pressure inside the transmission which could destroy it in less than 100 miles. STOP driving the vehicle until you get the MAF issue resolved. DO NOT UNDER ANY CIRCUMSTANCES stomp the gas pedal to the floor until this issue is resolved.

As a transmission shop we get called all kinds of bad names when customers come back due to a burned up transmission. The first thing we see when we plug the scanner in is MAF codes.. You ask them "how long has the check engine light been on?". Their typical reply.. It's ALWAYS on due to "X" problem.. Then you show them the MAF codes and kindly explain to them that the burned up transmission is 100% their fault for driving the vehicle with a bad MAF.. It is safe to say that your MAF situation is NOT your transmission builders fault, or responsibility, and your builder should not be required to fix any damage that results from your driving the vehicle with a bad MAF/MAF signal.

TXjeepTJ

iTrader: (8)

So weird, do you know why the MAF is connected to the transmission, like the logic behind that connection? Just seems like they are completely unrelated, though they obviously are related since this was my issue.

If you go into speed density, wouldn't that mean the PCM is making the transmission slip, since to get into SD mode, you have to trick the PCM to think the MAF is bad?

The transmission doesn't seem to be slipping, but I told the guy (this isn't my car) that he shouldn't drive it until we get the MAF fixed. I think he's going to be pissed, because he wanted to take the car to get suspension work done lol

LilJayV10

iTrader: (39)

Because it uses the MAF along with a bunch of other things to determine engine load which directly effects how the transmission behaves, line pressure, shifting, etc.

One the newer stuff, if you get a MAF code, it can disable the stabilitrak and a bunch of other stuff.

Kawabuggy

iTrader: (1)

Liljay nailed it!

TXjeepTJ

iTrader: (8)

It's just weird how when people go SD it doesn't seem to affect the transmission


I fixed the MAF (whoever did the wiring harness had 2 pins wired wrong). Transmission doesn't slam into gear and all MAF codes are back to being enabled. Thanks for all the help everyone

G Atsma

Glad to hear it! Thank you for reporting the happy conclusion!

markhodges78

Before the MAF the transmission used the TV cable to do basically the same thing

LilJayV10

iTrader: (39)

good post......

pdxmotorhead

I know its functionally a better system ,, but when ya think of all the code, all the engineering it too to replace a vacuum line , rod or a cable..

Dang..

markhodges78

Basically what I was getting at about the tv cable lol they never failed but seen plenty that were unhooked

LilJayV10

iTrader: (39)

I was serious. I apologize you took it in a negative way but I can see why you did. My wife also says I need to work on my communication skills.....

But yes you are correct. It's crazy what a cable used to do is now controlled by multiple computers and modules.

Why? Some of it is government. Most of it is our species has become a bunch of ******* pussies that need backup cameras, side cameras, top cameras for some reason and heated seats.