w203 SRS visit workshop

[bajicj]

I am going slightly mad with this car. I got c180 2001. The battery was going flat so I changed it. The new battery was going flat as well and after few jump-starts my indicators, central locking, windows, wipers etc. stopped working and SRS fault showing on display. Called mobile Merc mechanic who plugged in STARS and diagnosed fault to be rear SAM and window control module. Went to Merc, bought new and replaced. Next morning car wouldn't start again. It shows SRS warning. I went out and bought ANOTHER battery as I suspected the first new battery wasn't good (I bought it abroad and thought maybe they sold me a lemon). Next day was the same. I read some posts and saw that there may be a battery drain so I hooked my ammeter and unplugged the front seat modules, in-car lights fuses which also stopped a little fan in the courtesy light box to stop working and another 4 fuses, all connected with lights and seat modules. The current dropped to a very respectable 0.04A (before I unplugged seats and fuses it was 1.1A).
The next day - exactly the same problem. The car would not start and shows SRS fault. The funny thing is that if I pull the key out, put it in again and turn and do so many times, after about 15-30 minutes the car would start. Once it starts, if I drive it long enough, I can turn it off and on without any problems. But if I leave it for longer - same routine again. Any help is greatly appreciated.

 

[ABBY]

hi
if your car has front electric seats most probably your seat controller faulty.diode pack on alternator can cause same problem.
cheers

Abby

 

[bajicj]

Thank you Abby.
Alternator is just about the only thing I haven't checked yet - don't know how. Can you give me some pointers?

Thanks

 

[lynall]

But if its now showing a miniscule drain of 0.04A the problem is now not battery related as it still doesnt start, turns over but doesnt start.

Have you had the codes read?

Get a mobile mech to come and do it.


Lynall

 

[bajicj]

Hi Lynall,
thank you for response.
Last time the mechanic came out and changed the rear SAM and window module he ran STARS again afterwards and gave me the printouts. There were no faults showing even though we know now the route cause of the problem wasn't rectified, only the effect. The point is that the car starts EVENTUALY after series of dashboard lights blinking and beeps (all the lights on the dashboard flash and petrol gauge resets). This is with seat modules disconnected, so the problem is not there. I phoned the mobile mechanic again but he is somewhat reluctant to come out again and suggested I take the car into Merc garage. Any futher advice?

Thanks

 

[precious786]

hi there, i am having a similar problem, bajicj did you change the seat module and did it make a difference??

 

[markjay]

A couple of weeks ago my car (W203 180K 2006) went into a pothole and the 'SRS Visit workshop' light came up. it stayed on for around 20 minutes or so, then went away. Since then it did the same three times, for no apparent reason - while driving normally, it would come-up, stay for 15-20 minutes, then go away by itself. Any pointers would be appreciated... also, are there any tools out there that can clear this warning, other than the MB Star?

 

[markjay]

A couple of weeks ago my car (W203 180K 2006) went into a pothole and the 'SRS Visit workshop' light came up. it stayed on for around 20 minutes or so, then went away. Since then it did the same three times, for no apparent reason - while driving normally, it would come-up, stay for 15-20 minutes, then go away by itself. Any pointers would be appreciated... also, are there any tools out there that can clear this warning, other than the MB Star?

Problems solved

The error code was B1025 front seat occupancy faulty, and I cleared it with Autel MaxiDiag EU702. See also:

http://www.mbclub.co.uk/forums/general-discussion/88652-recommended-code-reader-diagnostic.html

 

[JOEY]

I bought one of those a few months ago, used it a few times and it now does n`t owe me.... good bit of kit.

 

[markjay]

I bought one of those a few months ago, used it a few times and it now does n`t owe me.... good bit of kit.

Well my problem NOT solved, the SRS message keeps coming back and I keep resetting it

On the plus side, every time I reset it using the MaxiDiag EU702 it pays back to me what it cost

I think I will have to take apart the connector at the base of the passenger seat and give it a thorough clean.

 

[jobela]

Try to get an electrician check the impedance of the plugs of the front sideairbags, they run transversally below the front seats. These should be around 18 ohms, it's an impedance adaptation for each airbag. Get an electrician that knows what he is doing.

 

[Diesel Benz]

Try to get an electrician check the impedance of the plugs of the front sideairbags, they run transversally below the front seats. These should be around 18 ohms, it's an impedance adaptation for each airbag. Get an electrician that knows what he is doing.

If the fault code was from the front seat occupancy sensor, isn't it more likely that this sensor is faulty (it is a common issue anyway)? Or do you think the non-official tool gave an incorrect code?

markjay, in my opinion you should fix the issue and not only keep clearing the code.

 

[markjay]

If the fault code was from the front seat occupancy sensor, isn't it more likely that this sensor is faulty (it is a common issue anyway)? Or do you think the non-official tool gave an incorrect code?

markjay, in my opinion you should fix the issue and not only keep clearing the code.

The code first appeared after driving into a pothole. This makes me believe that it's a contact that came loose somewhere, I doubt that the actual seat sensor can be damaged in this way. However, if checking the connectors at the base of the seat will not resolve this issue, off it goes to the MB dealer and I will be at their mercy as with regards to what need to be done.... I am putting it off because my experience with them so far has not been good.

 

[markjay]

Sprayed some WD40 on the connectors under the passenger seat today... see below.

 

[markjay]

Nearly two weeks on, SRS light not back yet... fingers crossed.

 

[markjay]

Nearly six weeks on, SRS light not back yet...

 

[markjay]

Nearly six weeks on, SRS light not back yet...

Problem did come back. But now (finally ) sorted.

Update here:

http://www.mbclub.co.uk/forums/interior/104511-w203-seat-sensor-calibration.html#3