I have a tps with too wide of a range, I know that. TPS was set at 0.5v. Scanner said 0.9. I checked for voltage drop between ecm and sensor. Everything healthy. Ground good. Reference signal good. Decided to adjust TPS based on what scanner said. Set at 0.55v. After doing that, reading at sensor read 0.33v. After that adjustment ecm is throwing code 21 for HIGH tps voltage. IIRC, that is for over 2.5v.

1) why am I getting a high code instead of low?
2) why is there a 0.4v difference between what sensor says and what ecm says when circuits are healthy?
3) when setting tps do I use value seen at sensor or value seen at ecm?

 

As far as I know, TPS has a range of 0-5v. Base setting at .54, WOT setting under a certain value, I believe it's mid-high 4.x volts. I've been told anything over 4v is read as WOT by the computer.

Not sure if your TPS is similar to mine, but mine adjusts two ways. You can adjust the rotation of it, as in turning it. Or, it moves forward or backward on the throttle assembly lever. In my case, my TPS was moved too far back, so when the throttle assembly rotated to WOT, my TPS read 4.86v, setting a code. Basically, it had a wider turning radius. Think of the two arms on a clock. They are both set at the same base. One is longer, and therefore reaches farther.

As for reading the voltage, I just used an ALDL cable to TunerPro RT, and read the voltage off that and adjusted as necessary. Just remember to adjust it at the base, then turn your throttle assembly to WOT to make sure the top end voltage isn't higher than say 4.40.

 

I'm gonna bring this thread back, just because I can't get the issue solved. I am on my 8th TPS, yes, 8th. I have checked the hell outta all the wiring. It's all reading what it should. However I'm getting the same discrepancy between what the TPS reads when backprobed, and what the ECM is seeing. I have an idle problem I'm trying to hammer out, but I can't move forward until I get this figured out.

If I set the TPS by what I read when backprobing it, I can sometimes get it to throw a code 21 when I romp on it. If I set it by what the ECM sees, I can get it to sometimes throw a code 22.

There is a gremlin hiding in my engine somewhere, and I've spent months not being able to find it. My IAC is reading in the hundreds at idle most of the time, my idle hunts bad, won't stay consistent over the course of a drive, and it's driving me nuts. I need to get this TPS issue hammered out.

Also, I'm using an ALDL cable and laptop with the latest release of tunerpro rt, and an a20converted definition. I can only get it connected if I short a and b...I cannot get data going with just normal settings, or using the 10k resistor like I'm supposed to.