CaliBenzDriver

After your reading of WIS bible you did disconnect the batteries: Yes / No ?

Supercharge

Perfect! I will get some pictures,more than likely tomorrow night. Thanks again...

Supercharge

yes, did both batteries and let it sit for half an hour then removed airbag..I assume this is the correct method..Internet never lies... haha

CaliBenzDriver

google around the name of your circuit board for a preview ... in case the pins are properly soldered, It'd be a chocker. Anyone else with us been in there??

Supercharge

Have you repaired or helped with a few of these n80 boards? At $240 it's worth opening up and seeing if these solder less joints are there to be fixed. I assume they all can be opened??

CaliBenzDriver

yes, you're starting to see the simplicity and the rewarding efforts.

no loose pins ... less problem ... more fun.

I have not dealt with busloads of E55 N80 SCM, you are now a pioneer geek ...congrats

The unfriendly modules to open are ECU, ABS/ESP, ISM,... harder to open and close. Everything else mostly cake walk.

DOOR MODULES are a lot of fun when windows have good power, sound faster with less glitches... over CAN-B, is it on W211 also?

Supercharge

CaliBenzDriver,

Here are the pictures of my n80 circuit board. It appears to have what you called solder less pins, or pins just pushed through the circuit board. Are you suggesting I apply solder to all of these pins that doesn't have solder? That is a super fine soldering tip for certain, wow. Let me know your thoughts...

juanmor40

Yes . I am waiting to have a free time to do this to my W212 SCM.

I already did it to the Rear SAM with help@CaliBenzDriver . Noticed he also suggested to check/fix your EIS (where keyfob goes) as well.

Supercharge

Where key fob goes? Mine has the push button start on the shifter, so would I need to do this?

juanmor40

You still have EIS on the dashboard, sister's W211 with the push start still has it. In fact, I use the key on that car when I drive it.

another post with documentation from @konigstiger

Here is a procedure forward the C-class
https://www.car-auto-repair.com/how-...nition-switch/

CaliBenzDriver

Quick fix opportunity 🤙

No way... check this out : things just couldn't be better for you: BINGO!

Your reward is available: free fix of your N80-SCM and more... !


Be careful searching for loose pins is amazing when you see how well your car reacts to micro surgeries - That why I call these "amazing pins": the results are amazing.

Say goodbye to an army of unnecessary grumblings you now know how to find.

I did a survey of modules with amazing pins.... (read my MBWorld links through my signature ).


a reliable circuit board

As Juan, @juanmor40 pointed out some incarnation of the ignition key pack another big reward in overall wheel performance... you'll see, I don't want to make early claims. You never know exactly what's in your car until you look ✌️

While you're dealing with N80 it's an extremely good time to deal with ignition for better rear access provided by working around steering column .

One more thing:
We get fancy but try not to forget the basics: check the circuit board inside steering wheel to see if your horn buttons are soldered or left to lucky pins??

Supercharge

Well soldered all the pins on the board. Placed it all back together, fingers crossed, but it didn't work..... Bummed.....

Any suggestions on next step? Can this board itself simply be bad?

Supercharge

I didn't see your suggestion to look at the steering wheel circuit board. Honestly read past what you wrote and went and placed things back together. I can pull the air bag tomorrow and look. Will I have to take anything part to see the circuit board?? Do you have pics of this one too?

juanmor40

Since you already assembled , perhaps time to rethink the approach if the focus is the horn

https://www.pelicanparts.com/techart...eplacement.htm

The circuit has effectively several failure points:
1- switches on the steering wheel
2- SCM, you already worked on
3- Relay at the Front SAM
4 - Horn themselves

However, you also mentioned nothing else in the steering wheel works, I read the cluster up/down switches do not work either. I would start from the internals of the steering wheel downstream.

Perhaps wiring diagram from WIS is needed to test the pins that connect to the clock spring. That is, what to expect at the pins when a given switch is pressed.

Post for another class
https://mbworld.org/forums/c-class-w...ml#post2739935

CaliBenzDriver

Juan is entirely right and to that I would add to READ THE SCM-N80 DATA for activities while exercising the horn buttons... This will help you figure where your horn signal is getting lost.

CaliBenzDriver

You need to take the time to do a little troubleshooting. At least you haven't overlooked the obvious. I am surprised your horn has more troubles - Use your scanner to read data.

Supercharge

juanmor40,

When I first noticed the horn didn't work I disconnected the horn and applied 12 volts to it and it worked just fine. Then I went to the fuse panel located on drivers side, searched and checked every fuse that would have anything to do with the horn. Then I checked relays and exchanged out relays, still nothing. Drove it and then noticed the buttons didn't work either. So then i proceeded to check all the fuses on the drivers side of the dash. Checked everything I can think of there that would be related to the horn and the control buttons on the steering wheel, again nothing.

So then I replaced the clock spring and now have tried the loose pins on the n80 card. Unfortunately still nothing. I will look at your other suggestions and see what I can come up with. A local independent garage i spoke with is backed up until the end of the month so I'm attempting to do what i can to figure this one out. Got me banging my head against the wall.

Supercharge

I don't have a high end scanner, simply $75 one. May need to invest in some Star software...

juanmor40

The process you described is the reverse one. In that case, the order is
1 - direct wiring the horn, check
2 - test relay. That is two step process. And you need a voltmeter, or test light. Relay must have a hot pin, 12 V, a control pins, for the module to activate, one to the horn.
So, you need to check out is live, i.e 12V check? If so, you need to direct connect hot to horn pin, using a fused wire, does the horn work? If so the problem is upstream; otherwise, problem is downstream (broken wire)
3 - does the control signal arrives to the relay location? A test light to ground and press the horn at the steering wheel. Check? If it does, the relay has a problem; otherwise, further upstream
4 - module upstream, N80? Not certain without diagram.
5 - test before N80, that is behind the steering wheel before the SCM. This test is to separate the failure points between harness/switches from N80 board.

​​​​​hope that helps

CaliBenzDriver

Here we are going to narrow down why your horn circuit is mute.
The SCM request F-SAM to activate horn relay through CAN signaling.

You can figure the horn relay pin-out and jump across the socket to energize horn... hunk-hunk?

Before SAM gets to switch power, it's all CAN signaling you can simply test conditions with a scanner.

If visual inspection doesn't help, then you go digital to look for clues. Now your N80 can be trusted better than new.

Supercharge

Thanks for all your help I will use what you have suggested here tonight after work and see what I can come up with. Again thanks!

Supercharge

I will look into this also tonight after work. Never performed the pin-out and jump across the socket before... Uncharted waters for me..

Heguli

If not Star, quality scanner (like iCarsoft MB V2.0) that can read signals is crucial when troubleshooting electrical problems on a modern car. I learned that really quickly when I started to resuscitate my car after total electrical death. Without a scanner you are going just by blindly guessing.

​​

Supercharge

I will look into one of these. Is it rowbust enough to help with what I have going on?

juanmor40

I have the iCarSoft specific for European vehicles. From the iCarsoft support group, they told me it is equivalent to the MB V2 version, and I can access all the modules. Will I buy it again after using the "hacked" XEntry installation? Not by any chance. I learned quite a bit from it, but I would not use it unless in a pinch (I keep it in the trunk compartment just in case)

To hack an XEntry, you need a decent old laptop (i5/i7 4th or higher generation), at least 256GB, a OBD2 interface device (Tactrix OpenPort 2.0, or better yet a VCX MB aware one) and the time to configure it. The expensive part will be the VCX MB-aware device. Of course, you can skip all this and contact BenzNinja and get a turn-key system as well.

Coincidence this thread (https://mbworld.org/forums/e-class-w...ml#post8771331 ) started today ?