TPS Voltage Question

[Spencan]

I have been looking at my data logs from Focus 9 OBD+ and I noticed that at Idle, my voltage is 2.95v, off Idle is 4.42v - 4.97v, and Full Load is from 3.54v-4.04v. The Idle is never as low as I have read, less than 1.0 v.

Do these seem normal?

[gb951]

delete

[johnb]

I have been looking at my data logs from Focus 9 OBD+ and I noticed that at Idle, my voltage is 2.95v, off Idle is 4.42v - 4.97v, and Full Load is from 3.54v-4.04v. The Idle is never as low as I have read, less than 1.0 v.

Do these seem normal?

I just checked mine (I happen to have my DME open at the moment). With the idle switch closed I have 2.9v and with it open (part throttle) I have 4.9. I didn't check WOT because I can't test it right now (the engine needs to be running etc.)

From my reading of the map it should be like this:

4.5v and up: part throttle
3.6 - 4.5: wide open throttle
2.6 - 3.6: idle
0 - 2.6: both idle and WOT

The last one above is the same mode you would get if you jump the diagnostic port as part of the idle adjustment procedure. It deactivates closed loop idle control but I don't know what else it does. My guess is that for maps and such it gets treated as WOT for safety.

So in summary your idle voltage and WOT voltage look spot on but your part throttle should never be below 4.5 if I read this correctly - that would be interpreted as WOT.

Where are you reading this 1v thing?

[Tom]

On the less than 1 volt thing, I wonder if you are thinking about the AFM signal going to pin 7 of the DME -- that once is generally below 1v at idle.

[Tom]

There was also some curious talk about the Focus9 data relating to the TPS in this thread -- not sure if that was ever sorted out and/or if yours might have development quirks still?

viewtopic.php?t=1163#p12003

[johnb]

There was also some curious talk about the Focus9 data relating to the TPS in this thread -- not sure if that was ever sorted out and/or if yours might have development quirks still?

viewtopic.php?t=1163#p12003

I just skimmed that and it was pretty interesting. Actually there was something in there might explain the odd part throttle voltage reading that the OP reported: because the WOT voltage range is between idle and part throttle, you have to transition through WOT to get from idle to PT. So as long as you're only seeing that voltage intermittently when transitioning, it's normal. The steady state voltage for PT should be 4.5 or greater.

Also it sounds like Joe also cleared up what happens when both idle and WOT signals are present - it doesn't count as WOT. So my guess was wrong.

[Spencan]

The less than 1 volt thing was on an a Google search and on some old posts from other sites.

It seems that my readings are normal and spot on with what you have posted. Thanks for the clarification.

I’m slowly learning how to read all the data that the OBD+ has to offer.

By the way, I just added a fuel pressure sensor to it and I plan on posting a detailed write up on it later this week…

[Evan]

I have been looking at my data logs from Focus 9 OBD+ and I noticed that at Idle, my voltage is 2.95v, off Idle is 4.42v - 4.97v, and Full Load is from 3.54v-4.04v. The Idle is never as low as I have read, less than 1.0 v.

Do these seem normal?

No, that's not normal. Your idle voltage is way too high. It should be below 1.0v. You likely have a bad TPS or it needs to be reset. Check for a worn spot on the throttle shaft.