Hello-

Hooked a Scan tool up to my Vette tonight. Only code it threw was "Code 22 TPS Signal voltage is too low"

I have been trying to get my car to run right for a while now and one of the steps I had taken recently was replacing my TPS. Is it possible I got a bum one? Or is there somewhere else I should be looking that could throw this code?

In addition, I don't know how, but in the process of removing the TPS to inspect and clean it I somehow cross threaded the lower hole on the throttle body that you fasten the TPS to. (Keep in mind the code was thrown before I did this.) I'm thinking I can chase out the threads but before a screw around any more does anyone know what size that hole is? What type of tap I would use? I have no idea how this happened, ok I guess I know how but I am just annoyed at this point.

Anyhow, if anyone can help me out here I would appreciate it.

Thank You

Bill

 

You will get code 22 if the TPS signal voltage is <0.2Vdc for 3sec with the engine running.

Take the good screw to the hardware store to find the correct die size then get the matching tap or (better) rethreader.

To check out your TPS, hook a DMM across pins A & B and watch resistance as you very slowly move the throttle through full range of motion.

If resistance increases smoothly, plug in the harness to the TPS, turn on the ignition and repeat the test while monitoring voltage.

 

The 90 is supposibly unadjustable. But I did drill a second hole right next to the other and filed the longated hole smooth so now I can adjust it between .51 and I think 5 volts.

 

I put some jumper wires between the TPS and the harness so I could test the voltage. I don't remember what the #s were exactly but the were not what you guys or the Haynes manual said they should be.

Now, bear in mind I replaced the TPS very early in this process with a brand new one. So untill I got the scan tool I did not think to go back there.

I bought another new TPS at NAPA yesterday. Brought it home, installed it and still didn't run right. I could hold it right to the floor, it wouldn't stall out completely but it would just about then rev up, cut out, rev up etc etc. Still idled great up to about 1/4 throttle.

OK, quick impression of me at this point....


OK, regained compsure and retraced my steps. Initially when I ran the scan tool and got the TPS error I cleared it, drove the car and it came back after about 2 miles. Then I didn't clear it again. I remember reading something about limp home mode where the car will run but in a safe mode of sorts. So I hoked up the tool- cleared the code and then let the car run a few minutes.

Here comes the cautiously optimistic part

I took er out and she ran great! Awesome power, throttle response, my baby was back! I put on about 35 miles during which I sut er off retsrted stooped started several times in case something else was the culprit. I just went for another ride this morning, still running awesome!!

I will keep putting more close to home trips on for a bit but I really hope and pray this did the trick. Thank you to everyone that heped me. Appreciate all of your time and support.

Bill