HELP: ECU wires cut & bypassed. what wires are they? CLK W209 re-map? Siren? Risistor

[dddooommm]

MBCLUB-



Please help-
On my CLK W209, on the ECU, the previous owner has CUT two wires and bridged a resistor across it. (see pictures)

(I'm guessing to tell the ECU that the said electrical component is "working" perfectly and putting out said resistance)

I was told car has been re-mapped, so I'm thinking it could potentially be this.

However my Delphi scanner shows only the car to have one fault on the whole car (yes I know, very rare for a Mercedes to only have one fault).
This fault is the car siren, It doesn't produce any audio alarm when triggered, only flashing lights.

I've looked to try to find an ecu diagram to work out the wires and I cant find it for the w209. Maybe a CDI W203 could be the same?
Part of the wiring harness has a tagged part number on it- Stating DELPHI electronics A5121500433
I think the part number for my ECU is: A6121536679 (CLK W209 CDI 2003 Auto English(

The wires on the block that I need to know is the grey wire and black/red stripped wire. The block is the second closest to the front of the cars front end.

Ideal Outcome: for someone to help me identify the wires. Hopefully the wires are for the siren so I can reconnect.
Or if its for the ECU aftermarket Remap then I will keep it how it is & wrap insulation tape around it.

>If MBClub members need me to find out the colours of the resistor on the wires let me know & Ill read them out.
>If MBClub members need me to find out what port number the wires are going into on the block, let me know and ill find out.



Many thanks in advance for any help & input,
DDDOOOMMM

 

[HughJarse]

Think I may recall that being needed for a headlight upgrade!?

 

[AMGeed]

Only suggestion I have is to look at the wires that are coming from the siren itself to check the colour code. It should be behind the n/s front wheel arch liner.

 

[grober]

All fuse/relay box details for W209 - Mercedes-Benz Forum

 

[Dec]

When triggered, the alarm siren should sound for 30 seconds and the hazards should flash for 3 minutes, if any of this doesn’t happen then the alarm siren is faulty, replacing or unplugging the siren should fix the fault.
Can’t see that the bypass wire having anything to do with the alarm system.
When locking with the remote fob, the hazards should flash 3 times, when unlocking the hazards should flash once.

Dec

 

[dddooommm]

MBCLUB-

Yes that's a possibility, I remember talks about headlight issues. The but the wire Looks like a cowboy 2 min job, I would have expected Merc approved people to take a little more pride, .i.e. shrink wrap, block wire connectors etc?

Also my siren is non existent....
I've recently taken the whole front bumper off (+front arches & front wheels)
I looked around for the siren (ebay searched w209, w211, w203 sirens to see what I was looking for)
All I found was a second car horn with wires connected...
May need to put a multi-meter on them I think & get someone to press the steering wheel horn to see which one of the two is the steering wheel horn.
Surely the two cant be the steering horn? if so why wouldnt they put them side by side?

Two horn locations:
1)Driver side upper wheel arch, near the front of the car (Under engine coolant tank)
2) Behind the merc logo, Front main grill.

 

[Dec]

Two horns are normal, as far as I know.

Dec
https://www.youtube.com/watch?v=BzmpeK1TFfw

[YOUTUBE]BzmpeK1TFfw[/YOUTUBE]

 

[dddooommm]

W209: Siren fault code is coming up as B1078 cabled fault

 

[Dec]

Either the siren is present but disconnected or has been removed from the car, either way its disconnection should show a cable fault.

Dec

 

[dddooommm]

Mbclub-

Thanks guys.

Plan of action for me is:
>check the location of the siren
>if it's there I'll multi meter it.
>if it's not there I'll put a used one in.
>if there's no wiring loom for it I'll track it from the ecu unit/ front Sam ?

Hope this post helps other people & not just me.
Still puzzled about the wire connection bypass on my ecu.

How can I check if my car has been remapped ?
If I take it to my local car performance garage will they have software/ hardware to read any aftermarket maps on my Merc?


Have a Good Friday evening !
Any advice is appriciated.
DDDOOOMMM

 

[Dec]

Don’t buy a used siren, the siren contains the ECU for the alarm system, the internal batteries can expire and cause damage to the siren PCB… see pictur… a replacement siren is around £100 from an MB dealer.

You can do without the siren if you aren’t concerned with security or theft insurance.

Not sure which side the siren is located, it may all be dependant on whether your car is left or right hand drive.

See… https://www.google.ie/search?q=w209...KEwiOj4zOga3KAhUFtg8KHUm5BjIQ_AUIBigB#imgrc=_

 

[dddooommm]

Afternoon MBCLUB

I had some time fee today to look at the siren alarm.

The small wiring loom for the siren alarm had been unplugged by a previous owner as they were tucked up neatly in a hole.

I replugged the wiring harness into the siren and intentionally set the alarm off by locking the car and putting my hand threw the open window.

It didn't have any audio siren, only lights flashing.
I cut a few fuses in half too. (One being the central locking)

So I put one angle grinder cut line into the security bolt which holds the siren to the bracket. This allowed me to get a large flat head screwdriver in to realase the bolt.

Opened up to see it dripping in battery acid, like dec said it would.

Off to order one from MB dealer and blagg discount again as the Merc is over ten years old.

Hope this helps people.



DDDOOOMMM

 

[richard]

Those wires go to the Intake Port shutoff motor on the 612 engine

I couldn't see them on the other engine wiring diagrams. Should be in pins 33 (grey) and 22 (black/red) if I am looking at the right diagram (i.e if you have a 612 engine)

All I know about that is its is expensive and I imagine has failed and someone has added that resistor to get rid of the engine management warning light. Aparently it fails due to a turbo leaking oil.

The fact that they didn't even bother to solder it in place suggests a quick bodge to me - but maybe it is something to do with the remap and they just forgot to solder that resistor in place properly etc.

Read this thread: http://www.mbclub.co.uk/forums/engine/114157-intake-port-shut-off-motor.html

Sorry to be bearer of possibly bad news.

Richard

[edit, i've noticed you mention the ecu is a A612 part number, so yes you have a 612 engine]

 

[dddooommm]

Hi Richard-

Ok that's news to me but I rather know! I will need to confirm that it defo is the part number to that engine. (I Cheated by looking at one on ebay with exact same spec and year as mine, educated guess)

I know I've got a leaking sump gasket, so common on these cars and plan of action is to fix it when I can borrow my mates ramp.

I'm tempted to remove the resistor and connect the wires back up so I can get a reading on my diagnostic system. Your thoughts Richard?

 

[dddooommm]

Is it easy to access? I cant recognise it, is it directly under the turbo?
I'm guessing i'm going to have to change the seals of the turbo and the intake shut off motor.

NewGenuine Mercedes-Benz OM642 Servomotor/ Inlet Port Shut Off Motor A6421500494 | eBay

 

[richard]

With your vin its easy to check.

I'd connect them back up and see what happens. I suspect an engine management light that won't clear.

R

 

[dddooommm]

M612 r5-diesel engine om612

 

[dddooommm]

I'm confused! I unplugged the resistor and put the original cables back to factory. I drove it around, waited for the car to reach temp then I kicked in the turbo at higher revs. No engine management light or No fault codes appeared on my dysgnostic system.

So I unplugged the wires with no resistor between any of them and no fault codes or engine management light came on.

Possibly the previous owners fixed the problem and didn't return the wires to factory position.

Plan of action: investigate condition of inlet port shut off motor, Replace if needs be. Replace the seal on the turbo as I can see it smearing out oil.

Thanks for any input

 

[richard]

So I unplugged the wires with no resistor between any of them and no fault codes or engine management light came on

Strange. I'm out of knowledge here as it is now oily mechanical bits I'll let someone else help.

R