fong

iTrader: (77)

I was trying to follow the manual to check my s5 n/a TPS using the special tool: two LEDs

according to the book page F1-83, in the middle of the page, it says:"1)warm up the engine, the stop it; 2)check the tps voltage as above; blah, blah..... then plug in the LEDs to the green 3 pins plugs, if one of the light is on. then it is ok; if neither is on, or both are on, then ajdust tps screw to make only one light is on". basically, that is what it says.

however, when I tried with the LEDs tool(from radioshack), no light will be on, no matter how I adjust the screw, while the engine is warm up, but not running.
when I checked it with the engine running, wooo, hooo, one of the LEDs is on. yah, my tps is working. well, the car runs fine.

so, is it possible that the book is wrong. we should run the motor when adjusting the tps????

SureShot

The FSM is correct, but there are easier ways...
The reason for warming the engine is to back off the cold start fast idle cam.
You can do that manually, even with a cold engine.

Here is my procedure:

Unplug the TPS connector.
Clip a cheap analog (needle type) VOM on the green & orange pins.
Set it to the 1K scale.
Hold off the throttle & work the short range TPS plunger in & out.
You should see a smooth sweep from ~0 to ~5K ohms.
Any bad spots or drop outs in the stroke - it's bad.
Find the fast idle (warm-up) cam & back it off so the throttle sits on the hard idle stop.
Adjust the setting to near 1k ohms.
While holding off the fast idle cam, open & close the throttle a few time to see that the 1K setting repeats.