Wire testing

Tiny
ROMANSING
  • MEMBER
  • 2006 MERCEDES BENZ SLK230
  • 1.8L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 78,000 MILES
I am trying to fix my car. The ECU is showing as faulty but it has been replaced without fixing issue. I have been told the harness may be at fault and found a mouse had been living in the car also.
I have oil slick in the connector area so will use electrical spray as described in article.
Also, I will test the wiring for brakes. Do you have a wiring diagram for the car (it is actuary a SLK 200 but its not listed)? Think you may be using a SLK in the article as it looks just like my car.
Wednesday, April 24th, 2019 AT 5:57 PM

13 Replies

Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

I will be able to help you with specific directions on how to test the wires, connector end views, connector pinout charts, ground locations and the like, but I need to be on the same page as your vehicle is. Can you please double check the vehicle year, make, model, engine size, and transmission type for me again, please. Be specific, please. This assures me I am finding the correct information for you, and that you are getting the correct information for your vehicle. Please get back to me with this information and we will get started.

Thanks,
Alex
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Wednesday, April 24th, 2019 AT 8:13 PM
Tiny
ROMANSING
  • MEMBER
  • 8 POSTS
Hi Alex

The car is a 2006 Mercedes SLK 200, 1796 cc, automatic. It quit running on me a year ago with the ESP fault code and the diagnostic came up with two ECU faults. I changed the ECU but same code was coming up. Either the replacement gad the faulty data transferred to it or it isn't the ECU. I have been told the harness is more likely the issue. I did find what looks like a mouse nest inside and I caught a mouse a few weeks later just yards from where the car had been sitting on driveway.
I can't see any wires damaged but they are so hard to see as they are covered by so many things in engine bay. I would love to get the car working again. My next step is to try to test the harness wiring.

Cheers,
Suki
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Thursday, April 25th, 2019 AT 10:55 AM
Tiny
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Hello again,

Both of my resources do not show a listing for a 2006 Mercedes Benz SLK 200. Could you please double check the year, make, and model of your vehicle one more time, or if possible just send me the Vehicle Identification Number (VIN)?

Thanks,
Alex
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Friday, April 26th, 2019 AT 2:32 AM
Tiny
ROMANSING
  • MEMBER
  • 8 POSTS
No problem. The VIN is:
WDB1714422F133687
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Friday, April 26th, 2019 AT 4:39 AM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

This is a European car. I do not have the resources for European cars. I have access to a Mercedes Benz SLK 230. I'm sure they are pretty close, but I'm not sure that wiring harnesses are going to be a spot on match. I can send you a couple of diagrams and you can compare them to what you have and we can see if they are the same if you want. Get back to us and let us know.

Thanks,
Alex
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Friday, April 26th, 2019 AT 7:46 AM
Tiny
ROMANSING
  • MEMBER
  • 8 POSTS
Okay Alex that would be magic. I will compare them and hopefully they will be a match or very similar.

Suki
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Friday, April 26th, 2019 AT 11:41 AM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

Okay, here is a sample of some Circuit Protection (Fuse Panels) from the closest vehicle I could come to yours. It is from a 2006 Mercedes Benz SLK280 with a 3.0L engine and an automatic transmission. Please compare these to what you have in your vehicle and get back to us with what you find out. There's a ton more stuff, this is just a sample for comparison.

Thanks,
Alex
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Friday, April 26th, 2019 AT 10:18 PM
Tiny
ROMANSING
  • MEMBER
  • 8 POSTS
Hi Alex,

Looks pretty much the same. Can you tell me how to test the harness between the ECU connector and the each of the sensors/actuators? And have you got the wiring diagram for the harness? Cheers

Suki
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Monday, April 29th, 2019 AT 7:36 AM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again,

Okay Suki, there is going to be a lot of information here so we will have to do this in sets of diagrams. Here is your first set. It is instructions on how to properly test wires complete with do and don'ts and best techniques for testing them. The next set of diagrams will follow shortly.

Thanks,
Alex
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Monday, April 29th, 2019 AT 2:07 PM
Tiny
SCGRANTURISMO
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Hello again,

Okay, here is your first batch of wiring diagrams. I will send you your next batch after you've had a chance to digest this batch.

Thanks,
Alex
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Tuesday, April 30th, 2019 AT 2:48 AM
Tiny
SCGRANTURISMO
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  • 4,897 POSTS
Hello again Suki,

Here is your next batch of wiring diagrams. Have you run into any variations between the wiring diagrams I am sending you and the actual wiring of your vehicle? I will wait to send the next batch of wiring diagrams until I hear back from you letting me know you're ready form them.

Thanks,
Alex
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Wednesday, May 1st, 2019 AT 8:13 AM
Tiny
ROMANSING
  • MEMBER
  • 8 POSTS
Alex
This is the right stuff but I have to admit being a novice its over my head. Gonna take me a while to work out how to use the diagrams before being able to test the ECU wiring.
Suki
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Wednesday, May 1st, 2019 AT 1:12 PM
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello again Suki,

It's just like reading a book. The electricity is always going to start at the top of the diagram. Notice how all of the fuses for the different circuits are at the top of the page. Then you just follow the wire down to the next component in the circuit, it could be a relay, a switch, a solenoid, eventually it will go to the circuits load. The circuits load is the whole point of the electrical circuit and all available voltage of the circuit should be dropped across the load. In a headlight circuit the load would be, you guessed it, the headlight. After the load, usually, there is going to be a ground. This is just as important as the voltage or (+) side of the circuit. You can tell a ground by three or four stacks lines with the shortest on top and progressively getting bigger on the way down. They look like a little pyramid. Let me know if that makes any sense or not, please.

Thanks,
Alex
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Wednesday, May 1st, 2019 AT 11:00 PM

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