2l 16v 9A Throttle Position Sensor

[bmwcompact 10]

My TP sensor (048 133 154) shows either zero ohms or infinity as soon as the throttle opens (I hear the click as I open the throttle). Should it not show a steady change in resistance as the throttle opens? Right now its simply acting as a switch to show the throttle has opened?

 

It seems to me that as its operating now its telling the engine ECU that the throttle is wide open whenever Im on the move. Maybe thats why my fuel comsumption is poor!

 

Info greatly appreciated. And if my TPS is duff where do I find a new one without paying silly money or will I be looking for a used one?

[lesarcsneil 0]

It isn't a throttle position sensor on the throttle body.

 

The electrical connector has connections to 2 switches, the switch that you've mentioned controls the Idle Stabilisation Valve (ISV) and is working correctly. The other switch closes at full throttle to increase the fuelling. When I had a faulty switch the resistance measured with a multimeter wouldn't give a stable value, it was constantly varying.

 

Is the car reporting poor MPG via the MFA on the dashboard or have you worked out the real MPG at the pump? The dashboard MPG is worked out based on vacuum pressure so it may be worth checking for vacuum leaks in the engine bay.

 

Neil

 

94 Flash Red 16v

[bmwcompact 10]

Thanks for the reply. But Im not sure we are talking about the same set up. Was this on your present 16v or on a previous car? My throttle body has a potentiometer on the end of the butterfly spindle connected via short cable/socket to the loom. It doesnt have a switch for full throttle unless you are saying its built into the potentiometer too. Ive seen photos showing a separate switch for WOT-I dont have that. Since the so called potentiometer costs over £100 I thought it must be a TPS and not just 1 or 2 switches.

 

I've only recently bought the car so cant be certain fuel consumption is high. The MFA on my golf gti and scirocco were both accurate, Ive checked all the vac hoses but havent yet filled the tank so not done a manual check. The reason I was investigating the various switches was because a couple of days ago the car started but wouldnt rev and kept cutting out-then it started to rev and was OK. This made me suspect the ECU was getting some false inputs. Posts here suggested the tps was often the cause of such problems. If anyone else has anything to add I would be grateful.

Edited March 12, 2012 by bmwcompact

[james153 0]

on a 2.0 16v the throttle body should contain a 3pin connector. Pin 2 being the earth. and 1&3 are Closed and Wide open switch feeds respectively.

 

If you wish to check if yours is working all you need is a simple ammeter and to carry out the following tests

 

pin condition resistance

1&2 Throttle closed Zero

1&2 Throttle Slightly open Infinity

2&3 Throttle closed Infinity

2&3 Throttle fully open zero

 

If youre getting anything else you have a faulty switch, if this is the case, then need to test the wiring to the ecu before condemning it. ill let you know which pins on the ecu if needs be.

[bmwcompact 10]

Thanks for your reply. So you also reckon this is not being used as a tps but just 2 switches. If thats so then I dont have a problem. I still dont understand why VW have used an expensive potentiometer instead of 2 position switches. Im sure thats all my Mk2 Golf and Scirocco had.

[james153 0]

KE-jet injection doesnt need a potentiometer as fueling is only electrically aided. its primarily mechanical. they may sell a modified part, although i cant see why. or maybe the guy at the dealer is trying to give you the wrong bit? who knows.

 

Can you describe your problem in a bit more detail and hopefully i can shed some light on it for you.

 

Thanks james

[bmwcompact 10]

[ATTACH=CONFIG]55725[/ATTACH]

 

For those of you who are unclear what a potentiometer looks like here is a photo. This is vw 048 133 154, Bosch 0280 120 426 which Vagcat parts catalogue says is the correct part for my 2l 16v 9A engine. It costs approx £120 from VAG. There are no other switches associated with this throttle. Normally such a device is called a throttle position sensor and feeds precise information to the ECU. Perhaps now readers will understand why I wished to establish whether this is a true TPS or just acting as 2 switches indicating throttle opening and throttle reached wide open!

[james153 0]

Yeah thats exactly what mine has got, auto data, previous knowledge, and the the injection system suggest that it comprises 2 switches. this can also be deduced from the tests previously outlined,

 

What sort of problems is this causing with your car? i.e. the symptoms?