Hey Guys,

I was curious to see if anyone knows about P0122 error code. Low Voltage to TPS?

I have a 04 VP (basically a DX if I'm not mistaken) Original Battery with nearly 50K on the engine. I have done all the maintanence to it. It through out the error and am almost certain that it is the TPS. The only thing that is making me think twice is that the engine has the whole "bucking" symptom, but it goes away after a couple of days. So I'm not too certain about it being the TPS now. I DO have the original battery and the green eye that is in it is pretty much black so I'm looking into replacing it. Could the battery cause anything like this?

I had the battery checked at Batteries Plus and they said that I have 2-3 cells of the 6 are dead. I stopped at Autozone and they say that it is a good battery. Who should I believe? Any help is GREATLY appreciated.

 

Check the wiring going to the TPS. The problem that P0122 describes is that the TPS sensor is sending a very low voltage to the PCM. This can happen if one of the wires going to the TPS is broken. If you were to disconnect the TPS connetor i think you get the same code. To diagnose if the problem is the wiring, you will need a scan tool that can display live sensor data. Connect the scan tool and look at the TPS voltage. If the problem is still present, the voltage is going to be very low, near 0v. Disconnect the TPS sensor. Voltage should go to 0. Take a paperclip and jump the TPS connector (jump the power and signal wires). This will send 5v to the PCM. Check the TPS voltage with the scan tool again. The TPS should show 5v. If the TPS is not 5v then the problem is with the wiring, a broken wire or loose connection somewhere. If the TPS does show 5v then the problem is not the wiring, either the TPS sensor or the PCM. To test the TPS sensor, disconnect the TPS connector. Get the voltmeter out and switch it to the resistance setting. Check the resistance of the TPS at idle and at WOT (engine should not be running). I think you will check the resistance b/w the signal terminal and the ground terminal on the TPS sensor (not the wire). The resistance should change (i think its going to be high at closed throttle and low at WOT).

 

Thanks Agent. Guess that's what I'm doing this weekend. I wasn't aware that there are scan tools that can display live data. Do you know if thats one of the ones that you can rent at Autozone? Now I know why the guys at the dealership were saying that they had more sophisticated instruments that are used to diagnose these codes. What had really thrown me off was the cost of the TB. The Dealership here was wanting close to $900!!! When I found it here online for less than $200 I was reliefed.

So first things first, remove the entire air intake box and get at that TPS cable. Is that Cable something that is readily available at auto part stores? or is it something that I have to go to the dealship to order? Once again Agent, thanks for your help and I'll keep you posted on it!

Mig

 

I think your way to quick to replace parts. First do the resistance test with the TPS connector removed. The scan tools at autozone most likely cannot read live data b/c they are cheap. You can buy a scan tool that hooks up to a laptop for $200 and its a really good unit. You can still do the TPS test w/o the scan tool but it is kinda difficult. WHat you will have to do is find the signal wire that goes form the TPS to the PCM(engine computer). Find the voltage between the TPS signal wire on the computer and ground. You can go and try to change the TPS but if its a wiring problem, you will end up paying $200 for a new TPS sensor and it still won't work. WHen you say cable are you talking about the throttle cable (the one that opens and closes the throttle) or a WIRE that carries electricity? If you are referring to the wire, you can usually tell if they are bad since you will see a wire that is broken but some of the TPS wiring is hidden which is the reason that you do the PCM test. The PCM test will tell you if there is a problem with that wire so you can go about finding which wire is broken. All you usually have to do for a broken wire is solder the wire back together and some electrical tape.