SRS light

[tahodgson]

The car is an '87 560SL. Thanks to Benzmac and others, I was able to remove the steering wheel and dash, and fix my earlier problem.

In the process, I found a dangling light bulb, and lo and behold, it's the SRS light, which now remains on when the car is on, even when the seat belt is buckled.

This car had been in a wreck before I bought it, and the fact that the light was disconnected from the dash leads me to believe that the dealer is clearly (pick one):
a) dishonest
b) inept
c) ignorant

Is there a code that needs re-setting when the airbag is replaced?

The replacement of the airbag and steering wheel is so fundamental that I'm virtually certain it's installed correctly. Battery connections are good. Found a lot of good information by searching this topic, but would love everyone's best advice.

Thanks in advance for your help.

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Tom

'87 560 SL
'74 MGB

[This message has been edited by tahodgson (edited 04-11-2000).]

[stevebfl]

Unfortunately the early systems don't have self-diagnostics. They will need to be tested with the MB tester.

If the light is on, the control unit isn't passing the self test. All the circuits can be hand tested and if they are good that means the control unit is bad. The control unit has to be replaced if the bag has been deployed as the crash parameters are held in the early control units. They can't be reset even with dealer tools.

On 1988 on vehicles the problem could be verified by retrieving the codes. A code ten indicates the bag or seatr belt deployment and tells the tech its time for a new box. All other codes are resetable if the problem is fixed.

At some point in the 90's the control units became programmable by the HHT and the replacement units have to be version coded for the number and type of bags and can be reset in most cases a certain number of times; seems like three but since I have never done it I can't be sure.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[tahodgson]

Steve,
Thanks for the background. In my search-related reading, I saw that there were some significant differences in the pricing of control units for various models. Is the 560SL unit one of the expensive ones?
This may not be worth the repair.

This is a unfortunate situation. My 420 SEL has the same problem. One day while driving, the light came on and never went out. The dealer said it was the control unit (crash sensor) and that the code would not reset. I had the steering wheel taken apart and that was fine, but no matter what the control unit code would not go away and they said it is $1100 just for the part.

I have never seen the part, but I think that price is rediculous.

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'89 420 SEL
'90 300 SEL
'84 300 SD (sold it)

[stevebfl]

[I have never seen the part, but I think that price is rediculous.

[/B][/QUOTE]

I'm sure half of it is for liability insurance.

We have goten good units used at a substantial price savings.

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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

My control unit code will not go out. If I installed your used one, the code will go out, right? What is the going rates for your used ones? Thanks.

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'89 420 SEL
'90 300 SEL
'84 300 SD (sold it)

[stevebfl]

The codes are kept in the control unit. Any codes from the old car will be carried to the new location. All the codes except the crash profile/manufacturers control unit code can be reset. If it has a crash code on the used one it is no good.

I mentioned that we had gotten used ones at a savings. I have never had any in stock. I search whenever necessary. I also would buy as close to home as possible when dealing with used parts.

Since you are from N.Carolina, I would recommend Potomac German Auto Parts they are in Frederick MD. 1-800-248-0091. They claim to be the world's largest MB salage yard.
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Steve Brotherton
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician

[This message has been edited by stevebfl (edited 04-12-2000).]

[tahodgson]

There are some things in life where the price matches the value of the product...but when a company has to build in massive product liability protection, that all goes down the loo.

I suspect that I'll simply pull the light bulb out, and rely on safe driving and seat belts (just as we did for so many years before airbags). I can't afford this one.

Thanks for all the advice, everyone.

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Tom

'87 560 SL
'74 MGB