Hi
I was wondering if Any one New how to test the TPS for the 325I. It has a round connector with 6 terminals. Unlike most of them I have seen with a square connector.
I have a rough and fluctuating idle so suspect it is this, as I have changed all board to iradicate leaks, New coolant temp sensor and cleaned icv.
Any help would be great![/img]
325i auto throttle position switch HELP..
Moderator: martauto
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
One section (three pins) is identical to the switches on the manual version, and the testing procedure is the same. The other three pins are a variable resistor (potentiometer), similar to that on an iS M42 engine, and on most cars produced since the E30.
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Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
Sorry, I don't have a circuit diagram for the electronic auto box, but the pins are easily identified with a meter.
Two of the pins will have a resistance of a few thousand ohms across them (5k, IIRC), and another pin will show a resistance to these pins which varies as the throttle is moved. These three pins are for the potentiometer, so the other three are for the normal TPS.
Two of these pins should show zero ohms between them, with the throttle closed, going open circuit as the throttle is moved off of its stop. With the throttle held wide open, there should be zero ohms between the only pin left, and one of the previous two, which goes open circuit again when the throttle is partly closed.
Wiki has details of testing the TPS.
Two of the pins will have a resistance of a few thousand ohms across them (5k, IIRC), and another pin will show a resistance to these pins which varies as the throttle is moved. These three pins are for the potentiometer, so the other three are for the normal TPS.
Two of these pins should show zero ohms between them, with the throttle closed, going open circuit as the throttle is moved off of its stop. With the throttle held wide open, there should be zero ohms between the only pin left, and one of the previous two, which goes open circuit again when the throttle is partly closed.
Wiki has details of testing the TPS.