Throttle Position Sensor testing

[Sam1977]

Hi guys

Starting a new thread on this as an off-shoot to my Z4M issue. So this isn't an M specific question, its a general question for all cars.

As part of my research I can see many people changing their TPS. Given that it seems fairly easy to test a TPS with live data I am wondering why people swap these as part of diagnosis: is it because the live graph data is not reliable or because its cheap to just swap them or something else?

Its not something I have ever swapped on a car simply because I have never needed to but since its in the frame on my general issue I am planning to test mine using a scan tool with live data graph before I consider it further as a potential issue. I can't actually do that today because the car is still at BMW but they don't seem to have tested this - just scanned for codes and I don't have a TPS code.

In my case I will be looking to see if when I hit the throttle I get a voltage dip initially that could make the car very momentarily run lean and cause my annoying problem of a quick rev drop.

Anyone else tested TPS in this manner?

TIA
Sam.

 

[Ducklakeview]

Live data won't be fast enough or have enough resolution to pick up glitches in the output. You need to get a scope connected to it so you can accurately see the outputs.

Mike

 

[Sam1977]

Live data won't be fast enough or have enough resolution to pick up glitches in the output. You need to get a scope connected to it so you can accurately see the outputs.

Mike

Thanks Mike.

So you would hook the scope up directly to the sensor to read the output rather than via the ECU (DME or whatever)? If so I guess that answers my question since at least on Z4M by the time you get to the sensor you may as well just swap it!!

 

[Ducklakeview]

Live data won't be fast enough or have enough resolution to pick up glitches in the output. You need to get a scope connected to it so you can accurately see the outputs.

Mike

Thanks Mike.

So you would hook the scope up directly to the sensor to read the output rather than via the ECU (DME or whatever)? If so I guess that answers my question since at least on Z4M by the time you get to the sensor you may as well just swap it!!

Yes. But having the wiring diagram to hand means you don't always need to get right at it to be able to scope it!

Mike