CarlosV

Good afternoon!

I have a problem with my CLK 200 (W209) cabrio pre-facelift from 2003. Yesterday I was installing a new HU from Pioneer, a appradio3, cause previously I had audio10 (cassete player) and I followed all steps I saw from other posts here on aftermarket HU instalations to my car.
I disconnected both battery cables, removed the dash panels and stock radio, instaled new one directly in the ISO terminals and only made the ACC 12V connection to the yellow/black wire from cigarette lighter and dimmer wire to blue/white wire. I also used Metra Acexx for the steering wheel comands and a Parking Brake Bypass. My car does not have any Boss AMP or Fiberoptics cable.
I mounted everything back in and tested and everything worked flawlessly. I did get an SRS error "Restrain System Defective, Visit Workshop" which I was already expecting.
However when I tried to start the engine, I heard a strange noise, similar to a fuse being blown and the car completely shuts off power. To get power back on I have to disconnect and connect the battery cables. It is possible that some electrical connection is wrong and producing a short circuit or because of the SRS error, it wont let me start the car, or something else even worse? Does anyone have a clue to what might be happening??

Rudeney

Check your battery voltage - should be 12.6v at rest and no less than 11v when you try starting.

CarlosV

Thanks Rodney but I think it wasn't from the battery.
I left the car untouched for a couple of days and today I tried to start it and it did without any trouble! So it is was a great relief for me! Still have that annoying SRS error but which I did not manage to erase by using the technique of rotating steering wheel completely to left and then right for 5 times... Maybe I'll need to connect the car to the diagnostics machine to erase the error.
The new HU sounds and looks obviously way better than my Audio10, so I do recommend people to do this upgrade!

Rudeney

The steering wheel rotation won't clear an SRS error - that is the procedure to reset the steering angle sensor, which is necessary when you get an ESP error after disconnecting the battery. Most all SRS errors are "permanent" and will require resetting with proper equipment (i.e. SDS). A typical cause of this when working on the radio is turning on the ignition when the upper control panel (where the "Passenger Airbag Off" light is located) is disconnected.

CarlosV

That is what I did! Ok I will need to take the car to the dealer then... Thanks Rodney!
Just one last question, even with that error, the airbags are working fine right?

Rudeney

I am uncertain about that. I have heard that any SRS error will deactivate the airbags, but I have been unable to confirm that.

GezaBMX

Hi Carlos,

Regarding the SRS, I have read on other threads that it can come on even if you start your car from the passanger seat since the car thinks that the sensor is broken in the drivers seat. I also have an SRS light from time to time but only when I have a passanger. Alos I have read that the wire tie is too tight in some cases and with time it slices the wire inside the seat.
Hope your SRS issue will get solved ASAP.

kennywong1234

That is same to me since i got passanger then I got SRS light on, how can we fix that or is it has to be back to dealer?

GezaBMX

Kenny you can try and take the back of the seats off and check if you have any issues with your wires and not the sensor pad that goes in the seat. Unfortunately when the SRS light comes on for good you need to take it to a workshop where they can cancel this error. For some reason it pops up on my dash from time to time but always disappears. I haven't taken the back of the seat off just yet since the weather is horrible here but I'll do the same once we get some nice spring weather.

kennywong1234

lol ok I try but it just weird cause it pop up like no reason, but thanks for your advice!

GezaBMX

Hope you'll have luck and it's going to be a cheap and easy fix

kennywong1234

Hello all, I finally had chance to open up my back panel on my seat and try to fix my SRS sensor on my seat, but I see all the wires are well connected so I think my only thing can do is to replace my sensor.

May I ask is this difficult to do and how much is the parts?
Thanks in advance.

DanielFD

wow, no need to go replacing parts if the SRS light is on.. did you reset the code yet?

kennywong1234

I'm only having the OBD bluetooth on hand, is that help? If yes I can try tonight!

DanielFD

Small generic OBD readers cant access airbag faults to clear them. U'll need either STAR or something more professional then a small generic OBD scanner. But dont try to replace anything in your SRS system before clearing the code. Like Rodney said its because you put the key in and the upper command was unplugged.

kennywong1234

Hi Daniel and others, so I took it to the shop and hook up with the pc, it's saying I have to replace the sensor of the seat first in order to reset the SRS light.

I'm not too sure can it be DIY, any advice pls?? I'm also awaiting the quotation from the mechanic but I think he will charge me like huge.. =(

DanielFD

Is that something the mechanic told you or did you read that? You can always reset the code, the code comes back when you turn on the car but it doesn't say you cant reset the SRS light before changing a part. Just be careful, whenever it comes to airbags and sensitive things mechanics seem to think your scared and you'll do anything they say.

DanielFD

Also take a look at this thread, the wires dont get cut in the back side of the seat, its under the seat from the back that they get cut:

https://mbworld.org/forums/clk-class...20-issues.html

kennywong1234

Yes the mechanic told me that to replace the seat sensor in order to get wipe off the SRS light.

I think he did reset it because i saw 1-2 second the light was off but it comes back again once he start the engine.

I asked him can I just get the SRS light off without replacing any parts but he said he can't.

DanielFD

Ok that makes sense now. Check the wires underneath the seat like in the thread i showed you. if those are fine it looks like the seat sensor is really shot and that will need replacing. Theres no way to turn off the SRS light without fixing the issue.

kennywong1234

Lol I checked that too and all wires are well connected, my last chance might be unplug all of them then replug everything again (like restarting all the hardware lol), but will that cause me screw up everything or what is the worse case?

Thank you Daniel again!!!

DanielFD

No problem at all! Actually you just need to unplug the Yellow wire connectors, Those are the only wires for the SRS system. If your extremely lucky it could be a dirty connector or the connector isn't plugged in correctly. Look at wires under the seat from the front and the rear, make sure its all plugged in correctly. But even if you were to find the culprit, there is noway you can know for sure. The SRS light wont turn off by itself, you'll still need STAR to turn it off.. Also your mechanic might have a heart attack when he opens STAR and every code possible pops up in front of him because you unplugged everything I'd remove the negative lead from the battery for 30min, that should reset everything but not the SRS light. If you do that expect your clock to reset and your windows and sunroof will need to be normalized (really simple, loads of threads about it).

CarlosV

Hey guys!
I didn't follow up this thread anymore but the problem was fixed. I took it to the dealer and they erased the error (was due to disconnecting the battery cables) and the error never appeared again.... Until last night, it just appeared again the annoying SRS light, but I am sure it is not related since it was one year after. So I am going to take the car to the workshop to see which errors come up. In the meantime I will also check the seat cables and put some WD40 on the belts buckle as suggested by some users here.
My passenger seat belt is also not working very well and the belt presenter stopped working two months ago. I wonder if that be related to the SRS light...

Another strange thing is that the other day I was cleaning my car and I found on the floor in the drivers seat a small glass fuse 3A/250V, like this:
*******/dP85sX
Any idea where is this from?

Sorry for all the questions, I love my car but it just seems to be giving me headaches after headaches... :S

GezaBMX

Hi Carlos,

Sorry to hear about the headaches. For me the SRS error appears sometimes when the passenger seat is used. Then again usually all I need to do is tilt the seat forward and push it back to it's place, this fixes it.

Hopefully you'll get everything fixed and enjoy your Benz!

@DanielFD the error disappears on mine and the funny thing is that even when it comes on and I stop the car it doesn't appear as a "malfunction" like a dead light bulb would show.

DanielFD

gezaBMX sounds like a weight sensor issue, they seem to a go a lot in our cars.