Thread: Tps reading .5 closed but onky 3.5 wot?!?!

All the obd1 cars ive dealt with have never had an issue being on or off. Voltage signal was identical either way. The ecu is gonna put out a max of 5 volts to the tps whether your battery volts is 12 or 14. Low battery voltage could possibly cause a problem but even then the ecu is set to output 5 volts. Which is why I asked him to check and make sure he has 5 volts to the tps. Unplug it to isolate it and check for 5v. Also check your ground to it as well by using the tps ground as the ground for your multimeter and then a good known ground such as on the battery post itself and see if you get different readings.

make sure the tab on the tps arm is not bent down. this will cause your low reading to be right and the wot to be low. I have only seen this issue on a tps when its bad or the tab is bent.

OBD1 FSM says the car needs to be on. For me, P11 with OBD1 ecu, it made a huge difference. Car off ~.40v car on .50v. WOT was off by more then .10v.

Well I wont argue the fsm. If thats the proper way to do it then so be it. Personally I havent seen any difference other than maybe .1-.2 running vs not running. In the end though for the most part i end I usually do it running anyways but have done it both ways and not seen a noticable difference.

Ve head....obd2. Unplugged I get 4.5-4.9 comin in as referance voltage. Car runs fine but my question is with a low wot reading will that cause the car to go slower or wat may it cause?

What TPS are you using?
Where are you reading the voltage, from the Consult port via software, or a DVM?
If DVM, where are you putting the ground lead, on the engine/chassis, or the TPS?

What's the max reading in these 3 states?
1) Accelerator pedal to the floor
2) TB open all the way by hand
3) TPS manually moved to maximum throw

C

Dmm, vvl tps ( 2 plug one), I'm grounding the dvm at a chasis ground( the ground wire that goes from thermostat house to chasis. Those reading are by hand throttle movement.

There are some enrichment tables that are based on TPS. You might go lean if the TPS is off, because it wont register as you pressing the gas 100% open, but 60-70%.

So I guess using a de tps is out of the question? Ve or p11(certain years only)

I'd be curious to see what the voltage reading is if you referenced ground at the tps itself. Another thought is to check the resistance, and post it here for others to compare against.

C