BMW N55 electronic wastegate

[mdhollis]

Has anyone integrated the HFS-4 failsafe into the new electronic wastegate the N55 uses? Just wondering if this will impact the way the wastegate operates since it is very different from the traditional solenoid controllers...

[Richard L]

I never had an opportunity to work on this. This is getting more common on newer cars.
Do you have such a need to make it work with the HFS4? The new Golf Mk7 uses it as well as the M4.

[mdhollis]

Originally Posted by Richard L

I never had an opportunity to work on this. This is getting more common on newer cars.
Do you have such a need to make it work with the HFS4? The new Golf Mk7 uses it as well as the M4.

Hey Richard..

Yeah I am integrating the hfs-4 with a jb4 so I could use the jb4 for the low failsafe but I would feel better integrating the Aquamist failsafe for high flow. Basically if the 0-5v flow sensor input to the jb4 is at 5V, which would be the case if I had a leak, the jb4 will map high boost and timing based on the assumption that meth is at max flow. I just would like the added safety of the wh as well as using the jb4 to handle no or low flow situations...

I am going to try to loop it through. I'll report back on any issues...

[Richard L]

If you are willing, I am very happy to have a go making this happen. But it will require some work on your part, measuring voltage from the electronic wastegate control valve. I believe there are five wires (pin number as below):

1. Motor (+) ...... [3B/46] DME connector/pin #.
2. Power supply(+) ......[3B/32]
3. Power supply ground ........ [3B/34]
4. Wastegate rod position ........[3B/33]
5. Motor (-) ............[3B/47]

I think the DME controls the direction of the motor on pin 1 and 5. Receive in real time the wastegate rob position on pin 4.

But manipulating the voltage at pin 4, you can drop the boost without using PID control loop. We are not trying to control boost here.

The first step is to measure the voltage on all the pins at idle of just ignition on. With those information, I can start my work.

[mdhollis]

Sure I would be more than happy to help. I'll post up results in this thread

[HYDE16]

sub'd for awesomeness.

[mdhollis]

Richard,

Here you go. This is with the engine off but ignition switched on. Did you want the voltages with the engine running as well?

F22 M235i


1. Motor (+) ...... [3B/46] - white - 1.41vdc
2. Power supply(+) ......[3B/32] - light blue - 4.98vdc
3. Power supply ground ........ [3B/34] - black
4. Wastegate rod position ........[3B/33] - yellow - 0vdc
5. Motor (-) ............[3B/47] - white w/ blue stripe - 1.41vdc

I verified the wire colors at the dme and also verified this is the same numerical order on the connector that plugs into the waste gate.

[Richard L]

This is great information, voltage. Thank you.

It is good to know there is some variations on the wire colours but DME pin # is totally accurate. If you can read the same signals whilst the engine is idling, it will be great. I believe if we manipulate the voltage on pin #4, we can control or disable boost.


I managed to find this OE wiring diagram, project ontop a solid start.

[mdhollis]

Engine running:

1. Motor (+) - 0vdc
2. Power supply(+) - 4.98vdc
3. Power supply ground
4. Wastegate rod position - 0vdc
5. Motor (-) - 13.82vdc

Richard I was thinking to measure a voltage on the wastegate rod position the connector probably has to be plugged in correct? Do you need me to figure a way to do that?

[Richard L]

In order to read the sensor with the plug connected, you need one of these:
http://www.posi-products.com/posiplug.html

Or strip the vinyl off.

I can send you a few if you pm me your address.

The information on the second voltage test is very useful. It showed the DME was reversing the motor to see if the pin 4 changes state, appeared to be a servo setup, looking for a feedback signal.