[Engine] turbo waste gate control

[Ivan]

Can anyone tell me what controls the wastegate 1.6hdi B9  .  My problem is the wastegate solenoid buzzers intermittently and then the turbo is bypassed.  It will be fine then for no apparent reason the vacuum solenoid starts to buzz and the voltage to the solenoid drops  from 12 volt, and shifts about 6volt. comes right again and turbo kicks back in..  There is also the step motor? which apparently controls the amount of gate open..  but why the vacuum solenoid and what controls it? perhaps a relay?

[cancunia]

Welcome.

There may be differences between the 8v & 16v engines and also the power rating of the engine as the higher powered engines have a VNT turbo.

[OMG]

Do you have any fault codes? The solenoid controls the wastegate and opens it when overboost is reached. Sound as if it might be faulty. Don’t know about the stepper motor. Just has wastegate with vacuums control for over boost on mine.

[brajomobil]

I had clogged vacuum tube to wastegate before solenoid.
It was on T-shape splitter. Solenoid was working ok.
There is no relay. It is controlled directly from ECU

Best regards,
brajomobil

[Ivan]

I had clogged vacuum tube to wastegate before solenoid.
It was on T-shape splitter. Solenoid was working ok.
There is no relay. It is controlled directly from ECU

Best regards,
brajomobil

I was using an alternative make replacement solenoid.. but have now got a Citroen item.. looks identical,  Original tested open circuit.  the 2 replacements both test 15 ohm.  I believe it is not a step motor on the back of the diaphragm.  It has 3 connections on the plug.  It apparently has a potentiometer and  senses the % open of the wastegate and keeps the control room informed.  Have replaced and all seems good at present.