SRS light on my CLC

[johncherokee]

I had my car serviced at MB Darlington, and they picked up a variety of faults that would fail the MOT. For some reason they failed to pick up the bright red SRS fault light. I have OPD’d the system and the fault code tells me that the seat belt restraining switch has a short circuit. Mercedes tell me they don’t have a replacement unit as the car is so old. Any ideas what I can do? I love the car, and am prepared to fix the other faults to get it through the MOT, but it’s pointless if it will still fail because of the SRS.

 

[markjay]

Second hand part off eBay?

 

[colinallcars]

I had my car serviced at MB Darlington, and they picked up a variety of faults that would fail the MOT. For some reason they failed to pick up the bright red SRS fault light. I have OPD’d the system and the fault code tells me that the seat belt restraining switch has a short circuit. Mercedes tell me they don’t have a replacement unit as the car is so old. Any ideas what I can do? I love the car, and am prepared to fix the other faults to get it through the MOT, but it’s pointless if it will still fail because of the SRS.

The part number is on it and it’s common to a number of models. As suggested, eBay.
You won’t have room to get a socket on the bolt, use mole grips.

 

[johncherokee]

The part number is on it and it’s common to a number of models. As suggested, eBay.
You won’t have room to get a socket on the bolt, use mole grips.

Thank you. After your post I had a look at the unit, and lo and behold the part number is on it twice, duh! I’ve ordered a replacement. Now I’ve got to find out where the electrical connector is..

 

[colinallcars]

Thank you. After your post I had a look at the unit, and lo and behold the part number is on it twice, duh! I’ve ordered a replacement. Now I’ve got to find out where the electrical connector is..

Under the seat. Just trace the wire.

 

[johncherokee]

At last I am mobile enough to have a look under the passenger seat. Lo and behold two connected wires and one wire out of its socket. Push it in and guess what, the SRS light goes out. Why did my code machine tell me I had a short, and why didn’t MB Darlingtonfind it?

 

[DSM10000]

At last I am mobile enough to have a look under the passenger seat. Lo and behold two connected wires and one wire out of its socket. Push it in and guess what, the SRS light goes out. Why did my code machine tell me I had a short, and why didn’t MB Darlingtonfind it?

Diagnostic scanners cannot detect that a plug is physically disconnected so the results are sometimes vague put point to a direction of further investigation which in this case it did.

Fault codes by themselves need experience and skill to interpret.

As for MB Dartford, why not ask them to explain their incompetence?

 

[johncherokee]

Diagnostic scanners cannot detect that a plug is physically disconnected so the results are sometimes vague put point to a direction of further investigation which in this case it did.

Fault codes by themselves need experience and skill to interpret.

As for MB Dartford, why not ask them to explain their incompetence?

I did ask MB Darlington why they did not comment on the SRS light, they said I only asked them to do an A service.

 

[markjay]

I did ask MB Darlington why they did not comment on the SRS light, they said I only asked them to do an A service.

 

[DSM10000]

I did ask MB Darlington why they did not comment on the SRS light, they said I only asked them to do an A service.

Well if you did only ask that then they had no authority to carry out any diagnostics which would have been chargeable.

 

[johncherokee]

Except one of the checks they have ticked off is the check of the airbags, and they won’t operate if the SRS light is on.

 

[zipdip]

Well I saw your post about the seat belt and thought I wwould suggest looking at the connection under the seat,having finished the post I see that it would have solved the issue,its always best to check the connections,sometimes just a alteration of the seat can cause a problem or to much shoving with a vacume cleaner ,well at least you have a spare if it does go wrong for real.

 

[markjay]

I suspect it may have something to do with your car's age. A CLC will be around 15 years old (or there abouts). Dealers shun older cars, especially the 'mundane' ones with low market value. They're thinking that the owner won't agree to pay £££ for diagnostic, and certainly won't agree to pay ££££ for the subsequent repair, so they'd rather just take your money for the service and keep shtum about anything else. Not a justification, but a possible explanation.

 

[johncherokee]

Well I saw your post about the seat belt and thought I wwould suggest looking at the connection under the seat,having finished the post I see that it would have solved the issue,its always best to check the connections,sometimes just a alteration of the seat can cause a problem or to much shoving with a vacume cleaner ,well at least you have a spare if it does go wrong for real.

It wouldn’t have mattered as I wasn’t mobile enough to have a look even if you had suggested it, but thanks anyway.