I have a 99 A3 Jetta TDI (ahu). I have an overboost issue that has led me to look at the N75 valve and the wastegate actuator. I think the actuator has taken some oil (not uncommon from what I hear) and made the diaphram mushy and not pushing the arm. Every thing else is moving freely. That is probably my overboost issue. When I checked the N75 valve it doesn't seem right. When I turn the key on (engine not running) there is a steady clicking from the valve. The + side of the plug is constant voltage and the - side that comes from the ECU is pulsing. When the engine is running this doesn't change. I have looked at other year TDI's and an older 1Z and they don't act the same. Turn the key on and the valve makes one click ( + side constant .... - side constant. I checked all the grounds for the ECU.
Any thoughts on this or is it possible it's the way it should function.
Topic: N75 ground signal (Read 3462 times)
