Scott.T

iTrader: (2)

Does anyone know how to set-up the TPS (Throttle Position Switch) on an MY99/00 ?

I assume one of the connections is an on/off throttle closed sensor and the others are a variable pot.

I want to check mine is set right, cause I have a feeling on v.light throttle it is telling the ECU that it is closed.

Also if anyone has the table of sensors and their expected output at the ECU connectior, it would be useful (I had one for my MY94, but have yet to locate one for the MY99/00).

Cheer.....

Dark Blue Mark

Turn the ignition on, engine off. Disconnect the TPS plug. There will be 3 pins. Put a test meter on it, ground on the middle pin and use one of the outer ones as a signal. Set the meter to Ohms.

Get someone to push the accel pedal flat (watch for carpet getting in the way) and take the reading. Then take a reading with the pedal up. You can alternatively move the throttle lever round if you're ambidextrous

You should get
0.5 +/- 0.3 Pedal up (throttle closed)
4.3 +/- 0.3 Pedal down (WOT)

Its easier than hacking into the ECU.

MB

Dark Blue Mark

Just to add, what are the symptoms of the problem?

Its much more ikely to be MAF / 02 / ISCV related IMHO.

MB

Scott.T

iTrader: (2)

Sorry, don't understand that at all.

If you are turning the ignition on, then removing the TPS connector, then you are removing the power from the TPS ?

Also how to you manage to read volts with the meter set to ohm's ?

MAF/02/ISCV have all been changed.
Both MAF and 02 were faulty before i.e hunting idle cure by new MAF and CEL32 cured by new 02.

The car drives fine, but on occasion at v.light throttle it feels somtehing like an idle/over-run fuel-cut has kicked in (I assume the Subaru does this as most injected cars do). Press the throttle a bit more and it's fine.

Dark Blue Mark

If you turn the ignition "ON" you have power to the sensor, even with the TPS plug out.

I didn't mention volts either the signal is resistance, therefore in Ohms.

MB

Scott.T

iTrader: (2)

But isn't there only 1 3-pin connector on the TPS.

If you are measuring Ohms why would you want the ignition/power switched on. Having power applied whilst connecting an ohm meter will confuse the meter.

Measuring between 0.2 and 4.6 ohms seems very low. You could easily get 2 ohms from the wiring. Also ohms are measured in parallel not series

The TPS runs off 5V as that's the regulated signal used on the DIY FCD thread (not that I have on efitted).

Dark Blue Mark

Look, thats just the way you test it!

Yes there is only one 3 pin connector. Middle pin for ground, outer ones for the signal.

I dont know why, but thats how I did it. Its pretty straight forward. Turn the ignition on. Unplug the sensor and check the signal. Just try it.

MB

Dark Blue Mark

BTW, you might be right with the voltage, but remember being told to set it to Ohms.

Been doing a lot of test meter stuff on the car lately, so might be confused. Its one or the other, so try both, it will be obvious which one is right.

MB

ScoobyDuck

iTrader: (1)

Scott,

MB's nearly there -but confusing us all - including himself by the sounds of it, eh Mark!!

basicly, it should be done with the connector still plugged in. ignition ON, and meter on VOLTS.

ecu connector B136
pin 12 = 5v
pin 24 = gnd
pin 21 = signal output

or u might be able to get on the plug - but its bound to be sealed!

the outputs should be

0.5v +/- 0.3 fully closed
4.3v +/- 0.3 fully open

YHM too

cheers
Steve

Dark Blue Mark

I wasn't referring to the ECU

I mean the plug actually on the throttle body. Pop out the black connecter and there are 3 pins in there. I got the instructions from Bob. Its a lot easier than breaking into the ECU wiring.

Right about the volts, I was thinking of a different sensor

MB

ScoobyDuck

iTrader: (1)

yeah - you can check the impedance of the TPS that way - which means you WOULD have to put the meter on ohms.
that would show if it goes 5Kohms -> 0 etc etc ...
anyway, im sure Scotts got enough to go on now !

Dark Blue Mark

I thought a bit of what I was thinking was right

MB