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Swirl Motor - cheap replacement solution (Pennies!)

489K views 572 replies 80 participants last post by  SixOfOne 
#1 · (Edited)
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.
 
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#2 ·
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
 
#4 ·
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.
 
#5 ·
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.

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.
 
#8 · (Edited)
The Resistor does work...forget swirl motors

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.:smile::smile::arms:

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.
 
#13 ·
Ha Ha...funny.
 
#15 ·
Variable Resistor.

Sorry not wanting to start a new thread on this there will end up to many but;-

Don't know if its been mentioned before but, the Turbo vanes alter under load on this turbo.
So I reckon the Resistor would have to be variable.
Turbo vanes must alter with speed or measured pressure, surely the vanes would stay at a certain angle that related to given speed/pressure for a smooth operation.
 
#22 ·
Sorry not wanting to start a new thread on this there will end up to many but;-

Don't know if its been mentioned before but, the Turbo vanes alter under load on this turbo.
So I reckon the Resistor would have to be variable.
Turbo vanes must alter with speed or measured pressure, surely the vanes would stay at a certain angle that related to given speed/pressure for a smooth operation.
I just spotted your post, you seem to be confusing turbo and swirl motor, they are both controlled seperately from the PCM with different functions.
The turbo has variable vanes as you have mentioned to give the best torque and bhp performance.

The swirl flaps are purely to lower emissions theoretically, but in practice are a waste of time, which is why they are removed/disabled on the likes of BMW VX etc.
The resistor is just simulating a load on the swirl motor to the PCM.

As you have discovered if the swirl motor fails or is disconnected the PCM throws an error and puts the car in safe mode, This is a combination of restricted turbo boost/rev limit and limited gears among others to enable the car to be driven whilst preventing potential damage.
 
#16 ·
Update....I did 25 miles today, my normal mixed town/ dual carriageway run, The car is running perfect and recording it's normal 36+ mpg...so why bother with a swirl motor?
 
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#20 ·
The swirl motor(amongst other things) determine where the actuator for the VV should be,it's been proven on here with that vid of the tugboat clock...lol...knick the signal off the swirl to make the VV work
 
#18 ·
thats what I've been saying for years,you don't need it or the flaps
 
#24 ·
As you know Ray we have been trying to figure out how we could disable the swirl flaps/motor without going into safe mode.
Simons idea of a remote mounted motor was a sound one but needed a working motor that may fail due to normal use.

When the Emulator turned up on Ebay that looked like the solution but at £100 it seemed a bit steep although there was no labour involved in removing the old useless motor,and Simon did fit one to a members car with good results.

We had a few theories about the contents of the emulator being resistors but no one tried it out.

I then spotted the resistor solution on the Merc forum and reported on here,but still no one gave it a try.

Next D5UPE came up with his guage method and although it appeared to work it seemed a bit involved...so I decided to finally try the resistor method and as we now know it works for the cost of a 26 pence resistor.

So Ray at last we can do away with swirl motors as you have been trying to convince us for the last couple of years:smile:
 
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#32 · (Edited)
Here you go,
Because this was a trial I didn't want to cut the wiring so decided i would fit the resistor by inserting the tails of the resistor into the pin holes of the plug.

on my car the plug wiring was below a bracket that secures the turbo and swirl motor to the head so the bracket had to be removed to allow the plug and wiring to be accessible,the bracket was refitted with the plug removed but it is possible to refit the plug with the bracket in place if required.
It's possible that a car that's had the swirl motor replaced may have the plug accessible without removing the bracket.

all i did was double over the end of the tails and push them into the pin holes and secured it with some insulating tape wrapped around the plug and resistor,the plug is laid on top of the fuel filter, if i need to refit the plug it is just a five minute job to remove the intake pipe and refit the plug.

The resistor is connected to the live and signal wires which are red/green and grey on the crd, these are actually the two centre connections on the plug, it is a four pin plug with three wires.

I'm not the best at explaining things so hopefully you can follow my direction and good luck if you give it a try.:smile::smile:
 
#33 ·
As you say a couple of matching spades would do the job if you do not want to cut the wiring.

It is worth mentioning that the connection can be made at the pcm,you only need to locate the grey signal wire and the live can be picked up under the fuse box for example.
 
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#34 ·
Thanks for the info, Boro al. It looks as if your method would be similar to the one I would use, should the need arise. I'm not sure I want to take this pre-emptive measure at the moment, but I can see the sense in avoiding the consequences of a swirl motor failure caused by the flaps jamming in a closed or intermediate position. Perhaps you could keep us updated on your car's performance with this mod after you've clocked up a few more miles?
 
#35 ·
It was done as a trial so while it is running ok i will leave it as is and see how it goes.
 
#38 ·
done it

Ok, I've done it.

It works. Walked down to Maplin bought a 4.7K resistor for 26p.

Came home, disconnected the dead Swirl Motor and just inserted the resistor into the Swirl Plug pings on the Grey PWM signal wire and the live Red/Green wire. The middle two on mine.

Ignition on, cleared codes on OBDII reader and fired her up. No further DTC codes, no MIL light, no ETC light.

Now its confirmed, I'll do a proper connection on it with spade connectors etc.

Big thanks to all those who've offered advice!!
 

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#41 ·
Ok, I've done it.

It works. Walked down to Maplin bought a 4.7K resistor for 26p.

Came home, disconnected the dead Swirl Motor and just inserted the resistor into the Swirl Plug pings on the Grey PWM signal wire and the live Red/Green wire. The middle two on mine.

Ignition on, cleared codes on OBDII reader and fired her up. No further DTC codes, no MIL light, no ETC light.

Now its confirmed, I'll do a proper connection on it with spade connectors etc.

Big thanks to all those who've offered advice!!
that 1st photo is a bit blurred...the resistor wire seems to go into socket #3 (top to bottom), does it also go into #2 (because the wire at upper end of the resistor doesnt seem to be attached)? (I'm guessing 2 & 3 from previous posts). Being ignorant of transistors, does it matter which way round its fitted?

for owners who have a working swirl motor at present, it may well be worth making up a spade connector / resistor set & keeping it in the glovebox JIC youre away from home & drop into 'limp' mode with a failure....... nothing would be guaranteed more than to have it happen on a holiday in France, for instance!


on a £600 repair, I reckon a £599.74 saving is probably worth having!

I'll alter the title of this thread & sticky it here & in Australia
 
#39 ·
Well done, Thats two of us now confirmed as ok, I can see a big drop in swirl motor sales.
 
#42 ·
Apologies for the quality of the first photo, taken on an iPhone. The resistor went in the two middle pins on my socket, #2 and #3, mine was a 4 pin connector but only 3 of them were used.

I just folded over the legs of the resistor and inserted them into the plug to make them fit whilst I fired the engine up and cleared the codes.

This type of resistor has no 'positive' or 'negative' end, so it doesn't matter which way around it goes.
 
#45 ·
I need to check the size of the spades,
If you check my post no 32 that will explain how to get at the plug.
 
#44 ·
Thanks KB for making my thread a sticky, I will try and get some decent pics from my car including a more permanent solution and also some pics of the EGR mod.:smile:
 
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