1998 CLK 230k compressor clutch

[Mafuta]

CLK 230k 1998. I had the star diagnostics done today at a indie. One fault that came up is the compressor clutch not engaging. It could also not be engaged remotely. MAS meter was ok.
The car has to go back for further investigation. I wonder if anyone has had a fault like this and what the remedy was. I am hoping some information will help cut down on the investigation time.
Thanks.

 

[television]

There are a few threads on this subject, I believe the clutch has now been dispenced with, and its now permanently engaged.

Malcolm

 

[Mafuta]

There are a few threads on this subject, I believe the clutch has now been dispenced with, and its now permanently engaged.

Malcolm

Thanks for responding. I have looked at the threads but have not found any answer (what the remedy was) to the fault I have. You are right the clutch is no longer used in later models but it is in use in the 1998 model that I have.

 

[jimsinessex]

Kompressor not cutting in

My 1999 CLK 230K also had this fault although the Star diagnostic gave the fault "air flap not changing over", this refers to the c/o air v/v between the air filter and the kompressor. Changing the v/v did not solve the problem. This turned out to be the komp clutch not engaging so the air v/v did not change over as the komp was not running.

Under the plastic cover at the front of the engine cambox is a 2-pin connector, one pin supplies a positive to the c/o flap to activate it and the other pin sends an earth to the kompressor clutch to cut the komp in. The earth signal comes from the ECU. This was the signal that was missing.
Now for the bad news, in my case it needed a new ECU to solve the problem.

I've since been advised by a member on here that engine ECUs can be repaired.

Rev the engine above 800 rpm and check for the the earth signal.

Before going down the expensive route try a dose of contact cleaner on the 2-pin connector and check continuity of the wire from the ECU.

Good luck, Jim

 

[Mafuta]

Thanks Jim,
I got an open circuit on the two wires going to the compressor clutch. Looks like I need a new clutch assembly.

 

[jimsinessex]

Mafuta

Did you check the 2 wires at the clutch or at the 2-pin connector I mentioned. The 2 wires at this connector DO NOT both go the clutch, one is the positive feed to the air c/o flap at the air filter, the other is the earth signal from the engine ECU to operate the clutch. My apologies if you are on the correct wires but I would hate you to have got a false diagnosis.

If indeed the clutch is faulty I am afraid MB do not supply it as a separate item, it means the entire kompressor assembly needs to be replaced, cheaper than the ECU but only just.

I unfortunately had the clutch bearing fail previously and had to have a new kompressor. The signal failure to the clutch happened a couple of years later.
Andy Gayle at www.mercedesservicing.com in Birmigham did the diagnostic work and it might be worth ringing him with your symptoms. He has a very good repution on this forum.

Jim

 

[television]

Mafuta

Did you check the 2 wires at the clutch or at the 2-pin connector I mentioned. The 2 wires at this connector DO NOT both go the clutch, one is the positive feed to the air c/o flap at the air filter, the other is the earth signal from the engine ECU to operate the clutch. My apologies if you are on the correct wires but I would hate you to have got a false diagnosis.

If indeed the clutch is faulty I am afraid MB do not supply it as a separate item, it means the entire kompressor assembly needs to be replaced, cheaper than the ECU but only just.

I unfortunately had the clutch bearing fail previously and had to have a new kompressor. The signal failure to the clutch happened a couple of years later.
Andy Gayle at www.mercedesservicing.com in Birmigham did the diagnostic work and it might be worth ringing him with your symptoms. He has a very good repution on this forum.

Jim

Jim, not quite right here, if you only have two wires, and one goes to the flap.that means that the other wire cannot be a ground lead in this case.
Where does the plus come from. I will try and look it up tonight.

Malcolm

 

[jimsinessex]

Malcolm,

The two wires I referred to were the wires at the 2-pin connector I mentioned which comes from the engine ECU, namely the positive to the c/o air flap and the earth to the kompressor clutch. The positive to the clutch must come from a separate source, possibly an individual fuse.

It seems logical that the ECU could handle the fleeting positive current supply to the c/o flap but I imagine the positive to the clutch would be continuous all the time the clutch is engaged and would not be supplied by the ECU. Hence the clutch current being switched at the negative (earth) side at the ECU, maybe through a relay.

I know for a fact that the two wires referred to are as I say as Andy Gale demonstrated that during the investigation into the fault on my car. I don't have a wiring diagram unfortunately.

This train of thought raises the possibility that Mafuta's fault may be a blown fuse somewhere although I haven't found one on my car, cheaper than a new komp or ECU eh?

One further thought, how was the "remote test" of the clutch operation done? Simply suppling an external positive to the clutch would not be enough as the earth side of the circuit would still be open circuit at the ECU.

Jim

 

[television]

Hello jim, I understand what you are saying, I think then that the plus connection has to be found, and with the ECU unplugged the clutch could be tested, I will have a look this evening and see if I can find some info.

Malcolm

 

[jimsinessex]

Malcolm,

Why would unplugging the ECU complete the earth side of the circuit for test purrposes? Remember the clutch is earthed via the ECU!

To test the clutch a test earth and a test positive would have to be supplied.

Any luck with identifying the source of the positive?

Yours, Jim

 

[television]

I am ashamed to say that I forgot to look, I have made a note, and will post later today.

Malcolm

 

[television]

Jim, its hard to work out without seeing the car, I have done you a print out ot testing the clutch, Please PM me with your address.

malcolm

 

[television]

3 pages mailed today, it seems to me that there are only two wires in total. any flap must be part of this and linked. As far as I can see, this would mean that one is a + the other - also means that one should get quite a low ohm reading. let me know what you make of the docunent.

malcolm

 

[Mafuta]

supercharger wires

3 pages mailed today, it seems to me that there are only two wires in total. any flap must be part of this and linked. As far as I can see, this would mean that one is a + the other - also means that one should get quite a low ohm reading. let me know what you make of the docunent.

malcolm

Hi The supercharger in question is as in the photo. As you see two wires in the plug going to the clutch.
I have bought a complete rebuilt supercharger from the USA. It would cost me more to purchase the clutch and have it fitted to my existing kompressor because of labour costs. It is quicker to remove the old unit and fit a new one.

Luis


"We are remanufacturing specialists in North Hollywood, California. Eaton M45 with a Electronic Clutch 2.3L is reassembled to meet or exceed OEM specifications. Tag reads A 111 090 03 80 Eaton 18036, Side Tag: CA29149. Pulley has 6 grooves and is 3 1/2 inch diameter".

 

[Mafuta]

Clutch assy

 

[Mafuta]

I am having no luck. I have fitted a new supercharger with a good clutch. The clutch engages when the ignition is switched on so the supercharger runs. My problem is the bypass valve it will not shut at any point. I do know the electrical power is supplied to it because with ignition off it is easy to manually push the flap shut, with ignition on there is a greater resistance on shutting the flap.

Please can someone help.
Luis

 

[Mafuta]

My 1999 CLK 230K also had this fault although the Star diagnostic gave the fault "air flap not changing over", this refers to the c/o air v/v between the air filter and the kompressor. Changing the v/v did not solve the problem. This turned out to be the komp clutch not engaging so the air v/v did not change over as the komp was not running.

Under the plastic cover at the front of the engine cambox is a 2-pin connector, one pin supplies a positive to the c/o flap to activate it and the other pin sends an earth to the kompressor clutch to cut the komp in. The earth signal comes from the ECU. This was the signal that was missing.
Now for the bad news, in my case it needed a new ECU to solve the problem.

I've since been advised by a member on here that engine ECUs can be repaired.

Rev the engine above 800 rpm and check for the the earth signal.

Before going down the expensive route try a dose of contact cleaner on the 2-pin connector and check continuity of the wire from the ECU.

Good luck, Jim

This is now the fault I have the "air flap not changing over". I was just wondering if the ECU recorded fault would have to be reset, remembering that there was an open circuit to the clutch. If the clutch would not engage and the flap would change over the intake air would be forced into a vacuum state only reduced by turning the supercharger. So my question is does the ECU automatically recognise that the clutch has been repaired (i.e. No longer open circuit).

 

[television]

Can you please let me have your Email address again,please include the first 6 numbers of your VIN. the 3 pages I have are for testing the turbo. Is the flap part of the turbo or on the manifold, its not on my pages.

malcolm

 

[jimsinessex]

Malcolm/Mafuta

The air changeover valve is item 86
I don't think I have quite masterered the knack of attaching pics, if it proves unreadable the valve is at approx 4 o'clock from the main body of the air filter .
It can be viewed at the Russian parts website, select the appropriate model of CLK, go to "air cleaner" and it is item 86 on the 4th pic down.

 

[Mafuta]

Can you please let me have your Email address again,please include the first 6 numbers of your VIN. the 3 pages I have are for testing the turbo. Is the flap part of the turbo or on the manifold, its not on my pages.

malcolm

No this is a supercharger related part, please see photo.

VIN number. WBD 208 347.

My email luis@araujo40.freeserve.co.uk.

Thanks for the effort in trying to help me Malcolm and jimsinessex.