Throttle position sensor tetsing

[scotsman60]

I have an intermittent idle problem in my wifes 1992 525i. I read the Bentley manual and then went ahead and tested the voltages and resistances on the throttle position sensor. The manual says that with the ignition on and the wiring disconnected I should get 5V between Pin 1 in the connecter and ground - Pin 1 is shown as the lowest (nearest the pavement) connector.

Now when I do this I get no voltage on Pin 1 but I get 5V on both Pin 2 and Pin 3. Is this an error in the manual or I am getting something wrong?

By the way when I tested the resistance on the opsition sensor I get no resistance change when I open the throttle so I plan on replacing it anyway but I just want to know if I've also got another problem.....



Doug