jky

2004 E55 The issue I am having is the recirculating air flap M16/7 it is 100% closed whenever engine is running no MB fault codes. Engine off the air flap returns to normal state.

OBD codes from the reaction of engaging the compressor, when the flap closed.

The compressor clutch is engaging as expected but no change with air flap. No modulation.

Is the bypass Actuator pin 4 motor positive, enabled with engine running and modulation of the flap is with the ground Pin 1 motor neg when compressor is enabled?

This issue started after getting it out of winter storage and driving it a several days. Car has 85k miles and no modifications. I have owned it a year and have no history of the car.

Harness is clean and dry. Ecu has some corrosion that I cleaned up and made no difference.

Any suggestions, I do not have a Star diagnostic, I have the ICarsoft MB2 that doesn’t see M16/7 only M16/6. If I had the Star diagnostic what other steps could I take and what else could I see in the sequence of the air flap. I have done the TB actuator reset several times with no change in operation.

Thanks In advance
Joe

Plutoe

Is it correct to assume that "whenever" means cold and hot?

drothgeb

Sounds to me like one of the potentiometers on the BPV might have **** the bed. My GUESS is it cycles positive to drive the valve but it's easy to check since your Valve is moving. Disconnect the plug and see what the resistance to ground is on pin 1 (on the ECU side). Start the car and see if it changes (as it would be attempting to close it as you are describing). You can do the save but read VDC of pin 4 to see if it's the positive that cycles the valve.

I might be able to check this weekend what you can see from the BPV in star. In simulation mode it doesn't show the BPV at all, but you can see all the values of both potentiometers and applied voltage and junk from the throttle body as you cycle it with the petal. This weekend I'll hook start up to the car and see if there is anything you can read out on the BPV in actual DAS because I couldn've swore I've seen it in there before.

Anyways like I said my thought would be a bad potentiometer in the BPV so the ME isn't getting the actual position of the valve, or bad contact on one of the pins in the harness maybe?

cnterline

When you find out what’s wrong patent it some guys are looking for that in their tune lol

drothgeb

Good point haha, OP hows it driving lol?

jky

Thank you for the suggestions.
Whenever the car is running start to off. Warm and Cold.
Flap is closed when running, if you unplug actuator and plug back the flap is open until starting car again.

Pin 1 to ground ignition on and not running, initialization cycle home position just past 90 deg .987 MΩ Closed during the initialization cycle briefly 1.49 MΩ then .997 MΩ opens to home position at .987 MΩ. Running ,closed .998 MΩ.

Confusing readings, Pin 1 to ground Turn car off at that point 287 Ω then 40 Ω quickly counting up by .1 Ω Unplug and plug back in still counting at same rate
I initially check resistance to ground before starting car of the harness connected to ECU and it was open.

Voltage pin 4 ignition on not running 12 v running 13.7
Voltage Pin 1&4 ignition on not running, initialization cycle .969 -1.22 peak 4.4 not the min max meter recording watching video of it.
Voltage Pin 1 &4 car running 1.89

I purchased a used bypass actuator, wasn't sure what else it would be. It shouldn't be closed in park at idle. Have it plugged in on top of engine to watch operation. It was disappointing that it did the same thing as the installed actuator.

Thank you for the suggestions.
Joe

jky

Not much of an update and not yet resolved.
Sent ECU to SIA electronics in IL to be tested for any water damage.
They cleaned up the corrosion but found nothing failed. Still no answer as to why the Flap closes with engine running and stays that way. Opens with power off.
Did purchase a star sd connect c3 to hopefully look closer into the function.
Check actual value of M16/7 and its correct ignition on engine off.
Actual value is reversed with engine running.

Relevant actual value voltage 1 4.2v
Relevant actual value voltage 2 0.8v
Specified values
Voltage 1 idle speed 0.7v
Voltage 2 idle speed 4.3V

The briefly blip throttle step is reversed also and actuator opens.

For the test of the Recirculating air flap.
Backwards again F4 open
F5 close
Functions as it should Manipulated variable and the feedback tracks perfectly.
opened it and closed it with this test several times.

No faults
How can this operation be reversed.
Can this be corrected with the programing by someone that has that ability.
SIA only checked hardware.
Who can check and correct function.
Suggestions.
Thank you

drothgeb

When you did the manual operation of the valve using actuations did you physically/visually verify the valve was moving to the correct positions it just saw the correct feedback voltages in star?

jky

I physically/visually verify with the used replacement sitting on top of compressor. It has responded the same as my current installed actuator. I have tested both functionally just able to clip on to wires on top for values.

Still no idea why but they both don't operate correctly and create no faults.
Plan to reverse the + and - on the motor and then test again.

Any idea why the operation would reverse for this actuator and still function.

Joe

StarvingArtist

The only thing I can think of that would do that is mixing up the TB plug with the bypass plug. They are physically interchangeable.

jky

I rechecked the M16/7 and M16/6 plugs Verified by switching them and the ESP fault code that resulted. Changed back and the relearn process completed for both. No fault codes
No fault codes stored in the ME-SFI 2.8
Thank you for the suggestion

Tylerhayles

little confused i have the m16/7 recirculating flap fault
intermittent, sometimes car is sluggish turn off and on then its ok again for a bit, what Should i check or do thanks

Tylerhayles

hey bud are you saying you switched the plugs and it worked? Or it didnt?