Checking the throttle valve potentiometer
On the fuel mixture preparation unit, in the direction of vehicle travel, is the throttle valve positioner (1) with its connector (2).
On the left: checking the throttle valve potentiometer: the resistance values you should obtain at the potentiometer terminals indicated here can be found in the table.
| Terminals | Test conditions | Resistance, Ω | |
| Manual transmission | Automatic transmission | ||
| 1 + 5 | 1 + 7 | – | 520 – 1300 |
| 1 + 2 | 1 + 2 | From throttle closed to approx. 1/4 open: resistance increases, then becomes constant | 600 – 3500 |
| 1 + 4 | 1 + 6 | From throttle closed to approx. 1/4 open: resistance remains constant, then increases | 600 – 6600 |
Right: checking fuel injector and intake air temperature sensor. The illustration shows the connector pin assignment of the multi-plug.
PROCEDURE
Disconnect the throttle position potentiometer connector.
Connect ohmmeter as specified in the table to two of the four connector pins.
If the specified values are not obtained, the throttle position potentiometer is faulty. Unfortunately, it cannot be replaced separately. The entire lower part of the fuel metering unit must always be replaced.
Test yourself
A quick Audi 80 quiz: every answer comes with an explanation and a link to the manual page.