What voltage should the orange TPS wire read?

[Saleenmav]

Looks like my TPS is bad, but I’m wondering if I don’t have another issue as well. Under the test procedures it states that the TPS should read 7.95V at WOT, however with the key on I’m only getting 6.2V from the orange wire that feeds voltage. Not seeing how it could ever read 7.95V without having at least that much input voltage.

Also, does anyone know testing procedures for the TPS of it’s not installed? I’m not gonna spend the asinine money on a new one but I want to be able to test a used one beforehand. Most times there’s a certain resistance range, but I can’t find anything.

 

[ripcuda]

In lieu of the proper TPS Test Harness... here's how I tested mine. Take a short piece of multi-stranded wire... strip sheathing off... unwind strands... get 3 separate thin strands... at least a couple inches long.

Unplug the TPS connector. Put 1 strand in each female connector hole and plug connector back in pinching the wire strands. Be sure exposed wire strands do not touch.

Unplug 2 wires on Port-side cylinder head temp sensor (it affects tps signal... by design).

Turn on key/ignition (do not start) (good battery important).

Find the correct 2 wire strands: at idle should see around 0.2-0.3 volts.

Move throttle to full/wot... check volts... should be around 7.4 volts.

Move throttle to zero and back to full a few times slowly while watching voltage... voltage should ramp up/down smoothly... not erratically jumping around.

If idle volts or wot volts are off... loosen screws on TPS and rotate (small amounts)... and retest idle-to-wot volts.

Get TPS in desired position and retighten... remove wire strands from connector... the end.

If you can't get TPS set... or it's is not smooth (volts jumping around) when throttling up/down... you likely need a new TPS (sorry... very expensive).

 

[Saleenmav]

Thanks for the follow up, but I have the testing procedures and have verified that my TPS is out of range (.785-.885v closed and about 2v WOT) but my question is what is the orange wire supposed to output? I’m only getting 6.2 volts on that wire, so there’s no way, regardless of what TPS sensor is in there, that it could read over 7 volts since a sensor can’t generate power. Before I throw money at this thing I want to make sure there isn’t another problem that is keeping the ECM from outputting the proper voltage. Or maybe there’s some black magic that happens and once you plug a good TPS in the ECM raises the voltage (doubtful). If I spend the money on a TPS sensor and I’m not getting the correct voltage to the sensor then I may still have a problem. Trying to avoid that given the price of the sensor.

 

[Tim75]

Thanks for the follow up, but I have the testing procedures and have verified that my TPS is out of range (.785-.885v closed and about 2v WOT) but my question is what is the orange wire supposed to output? I’m only getting 6.2 volts on that wire, so there’s no way, regardless of what TPS sensor is in there, that it could read over 7 volts since a sensor can’t generate power. Before I throw money at this thing I want to make sure there isn’t another problem that is keeping the ECM from outputting the proper voltage. Or maybe there’s some black magic that happens and once you plug a good TPS in the ECM raises the voltage (doubtful). If I spend the money on a TPS sensor and I’m not getting the correct voltage to the sensor then I may still have a problem. Trying to avoid that given the price of the sensor.

If you can find old stock p/n 14851, they are cheaper. I paid $120 4 years ago. Works OK still. Old style comes with round plug. 10 minutes with a soldering iron and the plugs are swapped out.

Sometimes entire manifolds show up on ebay complete with TPS for $250.
Yes, I understand- used parts.

 

[Tim75]

Thanks for the follow up, but I have the testing procedures and have verified that my TPS is out of range (.785-.885v closed and about 2v WOT) but my question is what is the orange wire supposed to output? I’m only getting 6.2 volts on that wire, so there’s no way, regardless of what TPS sensor is in there, that it could read over 7 volts since a sensor can’t generate power. Before I throw money at this thing I want to make sure there isn’t another problem that is keeping the ECM from outputting the proper voltage. Or maybe there’s some black magic that happens and once you plug a good TPS in the ECM raises the voltage (doubtful). If I spend the money on a TPS sensor and I’m not getting the correct voltage to the sensor then I may still have a problem. Trying to avoid that given the price of the sensor.

Did you disconnect the temp sensor wires before checking tps?
Is your battery fully charged?
Have you checked ground wires for green connections?