Swirl Motor - cheap replacement solution (Pennies!)

[Boro al]

Here is the solution we have been waiting for someone to come up with,

Credit to Alex Crow an independent Mercedes specialist and member of the Mercedes Benz owners forum.
The M55 is the same 3 wire motor fitted to the om642 CRD engine,
This appears to be the contents of the emulator but only costs coppers.

............................................................ .....
Inlet port shut off motor delete (CDI2)

A popular mod now, is to disable the inlet port shut off flaps, particularly on 270 CDI (612) engines.
This is usually done because of damage to the flaps from wear and tear, accelerated by EGR gasses.

It is possible to replace the entire manifold, but at significant cost, and some of these cars are old and unloved now!
Even if the manifold is changed, problems can still occur with the actuator motors (M55) jamming and signaling faults to the ECU.
So, how to do without the system...

To remove the flaps is simple, but leaves big holes in the intake manifold.
To plug these holes, I cut short sections of 16mm threaded bar, tap threads in the holes, fit the plugs with superglue, and finally drill and lockwire them for good luck.

With me so far?

But we still have a problem, if the motor is removed, a fault code will be logged, stating 'M55 inlet port shutoff motor signal wire resistance too high'.
Yes, the motor can be left in place and connected to the loom, and if working there will be no fault code.
However, as is often the case, the motor may have heavily worn gears, and frequently jam.
This will log a different code - 'M55 inlet port shutoff motor signals fault through ground keying', which simply means the integrated circuitry in the motor has seen that its mechanism is jamming, and has signalled a fault to the ECU by temporarily grounding out the signal wire.

So, if the motor is worn and jamming, we have a problem, but we do not want to replace it with a new one, especially now there are no flaps fitted.

Getting there now...

So, to cut to the chase, all we need to do to avoid logging fault codes, is wire in a resistor between the signal (PWM) wire and the 12v wire to the M55 motor.I have found that values from 1k to 10k ohms work - 20k ohms is too high.
I have opted for 4.7k ohms on my testbed, and so far all is well - no codes being logged.

I should add that you can buy these mods on ebay http://www.ebay.co.uk/itm/Inlet-port...item1e6a7d237e , but they are rather more expensive than a 4.7k ohm resistor...
Edit..
I have now carried out the mod..pics at post no 49.

[jackwalton]

Thanks for flagging this up.

If anyone cares to refer to a previous very long post about this very same issue they will see that I was certain there was a solution involving simple resistors rather than paying silly money for an emulator.

Well done and thanks for the info.

Jack

[Simon@thecustom300cshop]

Very interesting, I wonder why the emulator has so much stuff inside it then.

[Boro al]

AH! But does it have much inside,or is it a bluff, we won't know untill someone opens one up,

it may be like some of the cheap power boxes with a resistor encased in black mastic.

[devilmaycare]

Originally Posted by Boro al

So, to cut to the chase, all we need to do to avoid logging fault codes, is wire in a resistor between the signal (PWM) wire and the 12v wire to the M55 motor.I have found that values from 1k to 10k ohms work - 20k ohms is too high.
I have opted for 4.7k ohms on my testbed, and so far all is well - no codes being logged.

Its just as some of us surmised, even simpler than the two resistor solution that was originally proposed. It does seem a logical solution as all the ECU appears to be looking for is a voltage and current source that would indicate all is well in the swirl motor input. There is obviously no check on motor drive current, which is consistent with the workshop manual info. Zero impedance to ground or an open circuit are the fault conditions to be avoided. A small 4.7K resistor connected between the PWM signal wire and 12v would dissipate such a small amount of energy that it could probably be incorporated directly into the wiring loom without the need for any separate enclosure.

Originally Posted by Boro al

it may be like some of the cheap power boxes with a resistor encased in black mastic.

Somebody on one of the Audi forums opened up one of these boxes and found a microchip. I looked up the chip reference number and discovered it was an Ethernet interface (!!!). I suspected that the active component was probably just an internal resistor, but designed to fool the unwary.

[Kaiser Bill]

Originally Posted by devilmaycare

Somebody on one of the Audi forums opened up one of these boxes and found a microchip. I looked up the chip reference number and discovered it was an Ethernet interface (!!!). I suspected that the active component was probably just an internal resistor, but designed to fool the unwary.

that'll be for the exhaust cat 5

[devilmaycare]

Originally Posted by Kaiser Bill

that'll be for the exhaust cat 5

lol

[Boro al]

Originally Posted by Boro al

Here is the solution we have been waiting for someone to come up with,

Credit to Alex Crow an independent Mercedes specialist and member of the Mercedes Benz owners forum.
The M55 is the same 3 wire motor fitted to the om642 CRD engine,
This appears to be the contents of the emulator but only costs coppers.

............................................................ .....
Inlet port shut off motor delete (CDI2)

A popular mod now, is to disable the inlet port shut off flaps, particularly on 270 CDI (612) engines.
This is usually done because of damage to the flaps from wear and tear, accelerated by EGR gasses.

It is possible to replace the entire manifold, but at significant cost, and some of these cars are old and unloved now!
Even if the manifold is changed, problems can still occur with the actuator motors (M55) jamming and signaling faults to the ECU.
So, how to do without the system...

To remove the flaps is simple, but leaves big holes in the intake manifold.
To plug these holes, I cut short sections of 16mm threaded bar, tap threads in the holes, fit the plugs with superglue, and finally drill and lockwire them for good luck.

With me so far?

But we still have a problem, if the motor is removed, a fault code will be logged, stating 'M55 inlet port shutoff motor signal wire resistance too high'.
Yes, the motor can be left in place and connected to the loom, and if working there will be no fault code.
However, as is often the case, the motor may have heavily worn gears, and frequently jam.
This will log a different code - 'M55 inlet port shutoff motor signals fault through ground keying', which simply means the integrated circuitry in the motor has seen that its mechanism is jamming, and has signalled a fault to the ECU by temporarily grounding out the signal wire.

So, if the motor is worn and jamming, we have a problem, but we do not want to replace it with a new one, especially now there are no flaps fitted.

Getting there now...

So, to cut to the chase, all we need to do to avoid logging fault codes, is wire in a resistor between the signal (PWM) wire and the 12v wire to the M55 motor.I have found that values from 1k to 10k ohms work - 20k ohms is too high.
I have opted for 4.7k ohms on my testbed, and so far all is well - no codes being logged.

I should add that you can buy these mods on ebay http://www.ebay.co.uk/itm/Inlet-port...item1e6a7d237e , but they are rather more expensive than a 4.7k ohm resistor...

I had a nip to Maplins today and got a 4.7k ohm resistor 26p..well it is connected and the car runs as normal..no errors and no eml...I will leave it connected and see how it performs long term...
My swirl motor hasn't failed but theres no point in reconnecting if it's running ok.

I Think this solution would probably work for disabling the Egr valve also..I may give it a try next.
The thing is if the egr valve is blanked it still has to be disabled or overridden in the Pcm to prevent a error code and possible safe mode...You don't need to blank it if you disable in the pcm...it is closed by default.

[Armchair]

Nice one Al.

Do you connect it across the live and the grey(?) feedback wire?



Edit: Just re-read your original post and it looks like you do.

[matrix1975]

Originally Posted by Armchair

Nice one Al.

Yes, agree, nice one!

I'll have to give it a go. What 'wattage' of resistor did you use - or does it not really matter that much.

(You could probably write on a postage stamp what I know of electronics!!)