Transmission only shifts at high RPM's

Good afternoon,

Did it do this prior to the repair?

Do you have a scan tool that can tell me the voltage of the throttle position sensor at closed throttle?

https://www.2carpros.com/articles/automatic-transmission-problems

Roy

I have access to scan tool. I do not have one. It would take me a day or so to access it. I do have test meter. The first TPS I bought was bad. This one is reading right around 5v. Which tells me it's good. I have OBD tool. I have code p0481 which I know is fan. I have code Po141 which is bank One O2. I also have TPS code which is P0122. But I believe that is still there because I haven't cycled the car enough for it to read the new TPS.

I'm not very keen on transmission. But I wonder if the torque converter is not locking?

Sorry that was supposed to say 11.5 volts.

Okay, my voice text messed it up. 11.5 from the battery and 5 volts to the TPS sensor so I know it's good. Sorry about that so many messages.

Okay, first, if you have 11.5 volts from the battery, your battery is completely drained and I would charge it..

I attached a wire diagram for you to view of the TPS. What color wire did you test and found 5 volts?

The gray wire should have 5 volt reference.

I need the voltage from the dark blue wire at closed throttle with the key on.

https://www.2carpros.com/articles/how-to-check-wiring

Can you test that for me?

Roy

Battery was just about drained out. But good now. I still get 00.05 from dark blue wire. And 23.6 from blue wire with black line. With key in on position but not running and throttle closed.

Okay, let us start over.

You need to back probe the dark blue wire with the key on. You should have ,5 to .75 volts.
when you open the throttle, it should rise to 4.8 smoothly.

Test that and let me know.

Roy

As soon as i get off work today. I will do that.

Sounds like a plan.

Keep us updated.

Roy

So here is video with key in on position and car not running. Yesterday i had steady readings. But now battery is at 100 %. I'm thinking i will buy role of proper wires and collars. And just re run them with new plug. Then check. If you think that's good idea. I have two different voltage testers and they're both doing the same thing batteries may be low in them so I'm going to change those batteries and try that before I do everything else. But what do you think about this video?

The reason you have no readings is because you have the connector disconnected.

Put the connector back on and back probe as I stated in my previous response. You will get no readings with it disconnected.

Roy

It was not disconnected. It was on the battery ground. I couldn't hold both and roll throttle. Does that make a difference?

You had the connector in your hand. That is disconnected from the TPS. These checks are done with the connector connected to the TPS and you back probe the wires.

Roy

As you can see I have a dark blue wire next is a light blue wire with a black line it could be great. Then there is a green wire then there is a green wire with a black line. Your diagram shows black wire and opposite end of blue wire. So I use the green wire with a black line on the opposite end from my blue wire for my positive and negative on the meter I still I'm getting different readings. One time is jumping up and down the next time it's showing 1.49 another time it's showing 0.01. I cannot get an exact reading. I also tried grounding my meter 2 a bolt on the body of the car with vice grips and to the battery and I get the same thing all over the place.

I have 2 Monte Carlo SS's. One I'm working on is a 2000 my other one is a 2004 this is a picture of the two thousand four wires they are blue in green same as on my 2000.

Sorry picture didn't load. here it is:

Check the battery in your voltmeter.

You should be able to read at least the 5 volt reference.

Roy

Yes, like I said I'm going to get new batteries for both of my meters. Because they are both doing the same thing. I don't think it's coincidence but we will see when I put new batteries in them tomorrow can't get out tonight. thank you talk to you then.

Sounds like a plan.

Roy

I got busy yesterday. And figured i have time before bears game today. So i have new battery in both testers. And i'm getting 0.64 steady with throttle closed. And when i open throttle it goes down to around 0.50 then comes back to 0.64 and then stays there.. So i guess the TPS is bad. It all began after i put new intake gasket and cover. when i first started it the idle was really high at 3,000 RPM's. So I went ahead and changed the MAP sensor that did not work. So I changed the TPS that did not work. So I changed the temperature sensor that did not work. So i changed the idle air control or idle control and that worked. The idle came down. But then when I drove the car the RPM's were really high when shifting which is what we're discussing now. So I bought a second TPS. That's the one we're testing now. And clearly I got two bad TPS. I'm going to buy another one and try it. If it ends up messed up something is causing that to happen.

Plus i really didn't want to tell you because it's one of those mistakes you look around hoping no one seen you. Because you know better that to do it and not notice sooner. But here goes. The whole time i was testing the Idle Air control. Because it was the last thing i changed. And that's why both my 2000 and 2004 have 4 wires instead of 3. So stupid it's funny. Sorry. But the message before this is testing the TPS.

Pluss i really didn't want to tell you because its one of those mistakes you look around hoping no one seen you. Because you know better that to do it and not notice sooner. But here goes. The whole time i was testing the idle Air control. Because it was the last thing i changed. And thats why both my 2000 and 2004 have 4 wires instead of 3. So stupid its funny. Sorry. But the message before this is testing the TPS.

LOL, do not worry about it.

Yes, the TPS is bad. Replace it and retest to verify.

Roy

Okay, so all this time I was testing the wrong thing. Because my idle air control brought my idle down for some reason I kept thinking that was the throttle position sensor. And I know the difference I've changed them in many cars before. But thanks to you I finally stopped and looked at what I was doing in realized I was testing and changing the wrong thing. I put new TPS in and everything is great. thank you for your help. That was all my bad I can't believe I really did that but I did.

Good deal.

It is always nice to have a second opinion for the job.

Good job fixing it.

We are glad to help.

Roy

Question: I am replacing the factory mufflers with glass packs on my 2000 Monte Carlo SS. 3.8 V6. And I don't know if I should remove the catalytic converter or leave it in for the best sound quality without sounding like I'm trying too hard. And no I don't have to take emissions.

Okay, we are on to another car with another issue.

Please start a new question and I will be glad to assist.

Roy