W2037, coupe C220 CDi - Low Coolant Warning Light + Engine Fan Running

[Nick1964]

Hi, I'm brand new to the forum and wondered whether anyone can help with my problem. Car was driving fine when the low coolant warning light came on and the engine fan started running. Coolant level was checked and is fine; the temperature is also fine according to the temperature gauge. The sensor in the expension tank has been changed but the problem still persists. I've checked the fuses and found that the 7.5 amp fuse (fuse number 54) has blown and keeps blowing if replaced.

Since removing and refitting all the fuses and disconnecting and reconnecting the harnesses to the ECU (the one adjacent to the fuse box under the bonnet on the right hand side of the car) the ESP warning light has now illuminated; I don't know whether these faults are related. I've read threads regarding the washer bottle sensor and so have removed the harness from the sensor, still no change; I've also bridged the sensor harness connection (by inserting a link wire) and again still no change. Ther car now seens to be in 'limp home' mode as it seems to have little power.

Does anyone have any idea what this/these problems could be? It would be useful to know the resistance of the washer bottle sensor to see whether it's likely to be the problem without having to buy a new one unnecessarily. I have it booked into Mercedes-Benz Guildford next week for STAR diagnosis but thought someone may have heard of these problems before and be able to give me a pointer or two and maybe save me a few quid!

Also position and amperage of fuses would be very useful and the position and function of each of the relays would be good.

Very many thanks to anyone who can help.

 

[television]

Do not know this one,,could we have the first 6 vin numbers

203--- the next 3 please

 

[Nick1964]

Hi, first part of VIN is: WDB 2037062A; hope this helps!

Cheers,

Nick

 

[Cole@MBS]

Thats a front SAM fault, done a few of them now for the same faults!

 

[Cole@MBS]

Just re-read the first post as i thought i had missed something,

I had, looking at fuse 54 it controls the following, purge control valve, ME-SFI control unit and vent line heater element. so my first guess was incorrect, i suspect now that the purge Valve is u,s or poss the engine ecu! just a guess!!

 

[television]

Hi SAM I see the f54 drives the fan, and engine ECU and other things. I think the the engine is still running so we have 12 volts where there should not be,, it is in my view either the fan controller or the SAM N10/1

The ESP one can ignore as if the circuit has been broken, then just turning the steering will re set it

I wish that I could print the ledgends, then I could send him the diagram

 

[Cole@MBS]

Hi Malc, Yes, as i first thought , front sam, but something from memory also makes me think ecu! you said 54 does the fan as well? not on my info, doc number gf54.15-p-1256-o3p, are we looking at the same???

 

[television]

Hi Malc, Yes, as i first thought , front sam, but something from memory also makes me think ecu! you said 54 does the fan as well? not on my info, doc number gf54.15-p-1256-o3p, are we looking at the same???

I have PE54.21-P-2106--99FA its called wiring of front SAM control unit and relay module N10/1

Where F54 sits there is a wire that takes off to the left and goes to the engine fan control

 

[Cole@MBS]

We using different doc,s, sent you e,mail Malc! any ideas??

 

[television]

Nope thats a new one for me,,as is this one .

It needs more info,,I assumed that the engine is running, then if f54 is blown the ECU will have no +V and the engine cant run unless the SAM is leaking

 

[Cole@MBS]

And thats why the fans ars runnuing, not seeing a temp reading from the ECU!!

 

[television]

And thats why the fans ars runnuing, not seeing a temp reading from the ECU!!

Well thats the odd bit..where is the fan control getting its power from, its only a low current switching device, and the fan itself has its own fuse, SAM or fan control box, its impossible by remote control and no car

 

[Cole@MBS]

The main cooling fans have there own control module, if it cant see the PWM signals from the ecu, it hits default and goes flat out!

 

[television]

The main cooling fans have there own control module, if it cant see the PWM signals from the ecu, it hits default and goes flat out!

OK we do not have enough info to go further, I do know the F54 feeds the fan controller, on the diagram the take off is a little higher than the ECU junction

 

[Nick1964]

Hi Guys, F54 seems to feed the CDI Control Module (N3/9) and Intake Manifold Heater (R eight) according to GF54.15-P-1256-03P within WIS.

Regards,

Nick

 

[Nick1964]

ESP is still showing as a fault despite turning steering lock to lock 3 times; there is no exclamation mark within a yellow triangle unless ESP is turned off using the switch.

The car only revs to 3000 RPM now and both the 'Coolant, Visit Workshop' and 'ESP' warning lights are still on; and the fan engine fan is still running flat out as soon as the engine is started.

 

[television]

I am off now for the night, pick it up in the morning

 

[Nick1964]

Cheers buddy, all your help is very much appreciated. When you're back on-line can you let me know what the SAM is, what it does, whether it's repairable and if not whether it's an expensive item to replace (just want to have an idea of possible cost if it needs replacing). I can be contacted on 07812 244380 or am happy to call you if you send me your number (you can send this by e-mail if you like to: nick.medlock@ntlworld.com).

Cheers,

Nick

 

[Cole@MBS]

Item 10 in the link, that was my first guess, need some fault codes now i fear!

http://www.detali.ru/cat/oem_mb2.as...647716.651&CT=F&cat=69V&SID=54&SGR=084&SGN=08

 

[Nick1964]

Does that mean that the SAM is knackered or can it be removed, stripped and repaired? How do I get the fault codes or can these codes only be accessed by use of diagnostic equipment. The link that you provided is very good; is there a link to the whole manual somewhere?

Regards,

Nick