Insanely hard upshifting all of a sudden

[Derick]

Hey all. So those who read my trans post know that I'm semi skeptical about my trans rebuild. Today was a day like any other and as I was driving my shifting got insanely hard. I stopped to get my kid, turned off the truck and let it reset. Started it up and had a cel, p0102.

OK wtf. So I call the trans guy and he said that the maf can really wreak havoc on the trans if it's going out. OK so I quickly Googled it and seemed to support what he was saying. And in fact there appears to be 3 sensors that can throw off the tcm.

I stopped at O'Reilly and got 2 of the 3, a maf and a map. The new maf I threw in at O'Reilly and it didn't help anything. I replaced the map at home and i have the battery disconnected now to reset the whole thing.

So down shifting isn't a problem. It's only upshifting and 1 to 2 is terrifying. And we're not talking high revs here, 1800-2000 or so.

What do I do? Trans guy says that its electrical and not the trans (of course).. Any truth to it and what are my next steps?

 

[GreyStone]

When this happens on Grand Cherokees it is usually a transmission speed sensor.

 

[Doubeleive]

take it to him so he can drive it see what it is doing and then fix it, it's true the MAF can make the transmission do all kinds of weird stuff but if you put in a new one and the problem remains then that eliminates that theory. If he thinks it's electrical then he can hook up his scanner and verify that.

 

[Derick]

take it to him so he can drive it see what it is doing and then fix it, it's true the MAF can make the transmission do all kinds of weird stuff but if you put in a new one and the problem remains then that eliminates that theory. If he thinks it's electrical then he can hook up his scanner and verify that.

He's not local... It's a risk I took using him.

 

[Doubeleive]

He's not local... It's a risk I took using him.

sounds like time to invest in a tech2 or something that can read the transmission data so you can look for whatever this guy says it might be

 

[swathdiver]

Hey all. So those who read my trans post know that I'm semi skeptical about my trans rebuild. Today was a day like any other and as I was driving my shifting got insanely hard. I stopped to get my kid, turned off the truck and let it reset. Started it up and had a cel, p0102.

OK wtf. So I call the trans guy and he said that the maf can really wreak havoc on the trans if it's going out. OK so I quickly Googled it and seemed to support what he was saying. And in fact there appears to be 3 sensors that can throw off the tcm.

I stopped at O'Reilly and got 2 of the 3, a maf and a map. The new maf I threw in at O'Reilly and it didn't help anything. I replaced the map at home and i have the battery disconnected now to reset the whole thing.

So down shifting isn't a problem. It's only upshifting and 1 to 2 is terrifying. And we're not talking high revs here, 1800-2000 or so.

What do I do? Trans guy says that its electrical and not the trans (of course).. Any truth to it and what are my next steps?

You have to be able to see what those pressures are Derick. I can see them with the Tech-2 and the 6L80, not sure what you can see with the 4L80 in yours.

 

[Derick]

Im 100% onboard now that this is an electrical issue. Keep in mind I replaced the maf sensor last week, I moved the truck this morning (haven't driven it since this started) and it started like crap and has a p0102 code again. I'm convinced there's a ground somewhere that's whack.....where are the grounds and culprits on this beast?

 

[swathdiver]

Im 100% onboard now that this is an electrical issue. Keep in mind I replaced the maf sensor last week, I moved the truck this morning (haven't driven it since this started) and it started like crap and has a p0102 code again. I'm convinced there's a ground somewhere that's whack.....where are the grounds and culprits on this beast?

Do you have the scan tool and shop manual to following trouble shooting guide?

 

[Derick]

Do you have the scan tool and shop manual to following trouble shooting guide?

I don't have a tech2. Is there a service manual in electronic form? I can't remember if I've seen it for the burb or if it was for my former sequoia.

 

[BG1988]

Hey all. So those who read my trans post know that I'm semi skeptical about my trans rebuild. Today was a day like any other and as I was driving my shifting got insanely hard. I stopped to get my kid, turned off the truck and let it reset. Started it up and had a cel, p0102.

OK wtf. So I call the trans guy and he said that the maf can really wreak havoc on the trans if it's going out. OK so I quickly Googled it and seemed to support what he was saying. And in fact there appears to be 3 sensors that can throw off the tcm.

I stopped at O'Reilly and got 2 of the 3, a maf and a map. The new maf I threw in at O'Reilly and it didn't help anything. I replaced the map at home and i have the battery disconnected now to reset the whole thing.

So down shifting isn't a problem. It's only upshifting and 1 to 2 is terrifying. And we're not talking high revs here, 1800-2000 or so.

What do I do? Trans guy says that its electrical and not the trans (of course).. Any truth to it and what are my next steps?

let me know what fixes it i have a similar issue hard shift on first gear into second gear ( with light throttle maybe like 1100 rpm )
i replaced my Battery,air filter, MAF and map sensor so far..


some days it works "Perfectly" then maybe the next day it will run funny.. then maybe a couple of days later when i use it again it works perfectly like a Swiss watch