Mercedes-Benz Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter #1
I am just about finishing up on the 89 190d I picked up just over a year ago. I replaced all the dash lights with LED's and have one question. The SRS light is on and won't go off. I have checked through the entire SRS system and can't find any problems.

Just curious if anyone else out there has replaced the SRS bulb with an LED? Thinking maybe the SRS system checks for continuity through the bulb or something like that and with the LED it can't. I know that all the dummy lights stay on until the engine reaches 1500RPM since I swapped the bulbs for LED's

Thanks,
Chadd
 

·
Premium Member
'85 W201.601; '13 X204.651
Joined
·
745 Posts
I replaced mine and had problems with some of them fed through the 15 point connector. OK on most of the ones fed individually, like the turn signals. Finally just gave up on the ones through the connector and went back to filaments.

They worked fine on the bench when I tested to determine polarity but when it went back in the car, problems. Never found the answer and I didn't figure it was worth it anyway.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #3
Doesnt appear to be a bulb issue

I went ahead and pulled the cluster to swap a normal bulb back in but the SRS light is still on so I can only assume there is something else going on.

I have searched and searched but haven't found any definitive trouble shooting guide for the SRS system. Does anyone know if there are any diagnostic codes or anything that can be pulled out of the SRS system? My car is an 88 and not an 89 as I mentioned before.

The light comes on as soon as the key is turned on, even before going to the start position.

Things I have checked.

1. Seat belt connectors ohm meter shows ~400Ω with the belt unhooked and much lower with it plugged in.

2. Cleaned the contact ring on the steering wheel and column. Reads 2Ω through to the connector under the dash.

3. Unhooked the battery to see if it would reset it.

4. Removed and reinstalled the airbag and also tried another one that I have.

Thanks,
Chadd
 

·
Registered
Joined
·
35 Posts
Discussion Starter #4
got it fixed

Ok I got it fixed.

I used the 2 wire LED setup and followed the instructions from this pdf

http://www.benzworld.org/forums/attachments/w124-e-ce-d-td-class/357616d1297914152-how-do-i-diganose-my-mercedes-error-code-reader-reset-tool.pdf

Once I made the 2 wire LED setup I had several codes that needed to be cleared. But it also had a code 10 that means the sensor had been activated at some point in time, but didn't deploy the airbag.

I could tell the car had the left front fender repainted when I bought it. So it must have not been enough impact to set the bags and seat belt tensioners off.

I pulled the SRS module out of the parts car I have, put it in, cleared the codes and all is well. One thing to note though is that the SRS system doesn't like to have the normal bulb replaced with an LED. It will throw a code indicating that the error light is bad so I had to pull the LED and put a normal bulb back in it.

Thanks,
Chadd
 

·
Registered
1985 190E(SOLD 04/14/11) - 1986 190E - 1986 190E 2.3-16
Joined
·
105 Posts
Good to know as future reference. Thanks for sharing. :thumbsup:
 

·
Registered
1991 190e 2.6 automatic
Joined
·
760 Posts
i did replace all my lights with LEDS and i do have a SRS light on ( very dim almost cant tell its on ) and i dont remember having any SRS problems or anything... i think i never noticed it was on but it is def on dimly.
 

·
Registered
1992 190e 3.0 Auto (White)
Joined
·
33 Posts
Ok I got it fixed.

I used the 2 wire LED setup and followed the instructions from this pdf

http://www.benzworld.org/forums/attachments/w124-e-ce-d-td-class/357616d1297914152-how-do-i-diganose-my-mercedes-error-code-reader-reset-tool.pdf

Once I made the 2 wire LED setup I had several codes that needed to be cleared. But it also had a code 10 that means the sensor had been activated at some point in time, but didn't deploy the airbag.

I could tell the car had the left front fender repainted when I bought it. So it must have not been enough impact to set the bags and seat belt tensioners off.

I pulled the SRS module out of the parts car I have, put it in, cleared the codes and all is well. One thing to note though is that the SRS system doesn't like to have the normal bulb replaced with an LED. It will throw a code indicating that the error light is bad so I had to pull the LED and put a normal bulb back in it.

Thanks,
Chadd
I'm sure if you matched the resistance of the normal bulb it wouldnt notice.
 

·
Registered
Joined
·
35 Posts
Discussion Starter #8
I'm sure if you matched the resistance of the normal bulb it wouldnt notice.
There is no way to match resistance between a bulb and an LED. A bulb is pretty close to a short at low voltage where as an LED has a fixed voltage drop of 1.5-2.1 volts before it will pass any current so there is no way to do a check to see if the LED is good like you can with a bulb. This is the reason why all the warning lights stay on until the engine hits 1500rpm because the car thinks all the bulbs are bad.
 
1 - 8 of 8 Posts
Top