Why is my 4L80E shifting weaker?

TacomaJD · Mar 2, 2014

Re: Re: Re: Why is my 4L80E shifting weaker?

grcthird said:
The P0107 code is for the map sensor, the U0107 code is for the throttle body actuator, the programmer software probably has a glitch with which description goes with which code, since the truck computer only "gives out" the code and not the description. (You could "test" this theory by unplugging the map sensor and seeing if it throws the P0107 code.)

Going with the U0107 code:
Lost Communication with Throttle Actuator Control Module
Check the ground wire on the left rear of the engine block, lots of issues with it being broken.
Test for 12 volts on the Pink wire at the Throttle Actuator Control (TAC) module and look for loose terminals. (Back probe it with a paper clip while it is plugged in and ignition is on.)

Basically it is either the throttle body, wiring between it and the computer, or a bad computer. My money is on the ground wire being bad or the throttle body.

I've been at work all evening and my truck is with dad. He's been working on it today while I'm working, since he's off today. Exchanged my throttle body with a used one, made no difference. MAP sensor was only $52 from Advance, so it now has brand new MAP sensor on it too.....made no difference. Maybe it's the damn computer. This truck has never been wrecked, I take good care of it, and it is in excellent shape under the hood. Wiring harness is still factory wrapped and taped up tight, and nothing is noticeable in terms of wires being loose, broken, or anything else.

Is there a separate throttle positioning sensor? Or is that basically what the throttle actuator control module is that's on the throttle body itself?

grcthird · Mar 2, 2014

You can call the service dept with your vin and they will tell you over the phone if it has an open recall.

Did he erase the code after swapping throttle bodies? It may have to relearn closed and wide open positions.

grcthird · Mar 2, 2014

Did you fawk with any other fuses and leave them out or check for any others that are blown?

zukimaster · Mar 2, 2014

See there! look at all the parts that have been changed and the time spent, carry to the chevy store asap! you will be money ahead! And i would not want anything but GM parts on there if at all possible, those aftermarket parts are a crap shot sometimes. I had a buddy awhile back with a Bronco that went to acting up, after the first couple hundred bucks and it didnt fix it, told him to just carry to Ford store, He didnt, ended up at 3 different shade tree places, spent almost a 1000 bucks changing everything under the hood, still did not fix it, carryed it to the dealer, took about a hour to diagnose it, bad computer, they charged him 68 bucks, and the used computer was 75.00. see the morale of this story

ibrokeit · Mar 2, 2014

zukimaster said:
See there! look at all the parts that have been changed and the time spent, carry to the chevy store asap! you will be money ahead! And i would not want anything but GM parts on there if at all possible, those aftermarket parts are a crap shot sometimes. I had a buddy awhile back with a Bronco that went to acting up, after the first couple hundred bucks and it didnt fix it, told him to just carry to Ford store, He didnt, ended up at 3 different shade tree places, spent almost a 1000 bucks changing everything under the hood, still did not fix it, carryed it to the dealer, took about a hour to diagnose it, bad computer, they charged him 68 bucks, and the used computer was 75.00. see the morale of this story

He aint gonna listen.

BUG-E J · Mar 2, 2014

ibrokeit said:
He aint gonna listen.

BWAHAHAHAHA. That's why I haven't gotten into this one too much. I woulda told him take it to the dealer to start. I have delt with a few tb issues on some used cars at work and they always end up being a nightmare that we have to send to chevy dealer.

TacomaJD · Mar 4, 2014

Re: Re: Re:

TacomaJD said:
So just so we're clear on references here, TAC is the technical term for throttle body?

This was incorrect, fwiw. Throttle Positioning Sensor is the thing that is mounted (via rivets) to the throttle body itself. TAC is a seperate box that has 2 plugs going into it. Which is what the U0107 code was signaling. Truck is in shop now and they think it is the TAC. Gonna swap out TAC with a good one tomorrow and see if that fixes it. They said Throttle body, TPS, wiring, and plugs looked good. Figured it to be the TAC.

They are also going to troubleshoot my blinker issue where my front and rear driver's side blinkers do not work. Sweet timing for all this ****. Glad I'm gettin' a little back on tax return and am getting a good bit of overtime at work. Finally get my money right to buy rest of link **** and the tow digger ****s up.

TacomaJD · Mar 4, 2014

Called and said truck is ready to go. I reckon it was the TAC module and they also said they tracked down a broken wire causing my blinkers to mess up and fixed it.

Grand total of $125. We'll see how it goes when I get to drive it, I guess.

zukimaster · Mar 4, 2014

Glad you got it fixed, see how easy and cheap it is to let people that know what there doing mess with it, glad you gave in early and didnt spend anymore money and time ****ing with it.

TacomaJD · Mar 4, 2014

zukimaster said:
Glad you got it fixed, see how easy and cheap it is to let people that know what there doing mess with it, glad you gave in early and didnt spend anymore money and time ****ing with it.

Wasn't much else we knew to do BUT to carry it to the shop lol. Auto Tech in Section is who fixed it. Dad knows Craig Newsome real good so he done me right. Got the replacement TAC module from dad's work for free, $125 to the shop for fixing that and the blinker issue, and $52 MAP sensor that it didn't need (that was dad's doings), but the bright side to that, is I have a spare MAP sensor now, so fawk it.

I'm glad it didn't cost any more than that, I was worried it was gonna be pricey when they got done with it. Toyota shall be hauled to Angryfab this weekend! :woot: