2010 E350 c207 connected battery terminals wrong

[paul831]

Car was laying over winter and battery died.
Bought new start/stop battery.
Connected to the wrong terminals for about 5 secs.
Car wont start now and getting the below fault.
Checked voltage at pre fuse box all ok
Checked all fuses beside brake fluid all ok
Also checked fuses in boot all ok.
Dont seam to have a fuse box at side of dash
Any help on where i should be looking next

 

[martyz]

Should be in the boot on left hand side behind a pull off panel.

 

[paul831]

IS the rear sam the whole fuse box in the boot as per photo ? Or is there a seperate module as fuses are ok in boot also rear lights are working however the radio is not working tho suspect thats the fuse in behind it

 

[Diesel Benz]

You must have changed the main battery, not (only) the start/stop battery (if a MY2010 car even has one)? A fully charged battery connected then the wrong way? You need to check pre-fuses too. Lucky if only fuses gone.

And yes, the whole thing with fuses and relays etc. is the rear-SAM.

 

[martyz]

yes that's it if fuses are okay you may have damaged the components which would mean replacement.

 

[paul831]

Is there a way to test if the rear sam needs replaced as i know there are multiple isssues that can give the fault

 

[paul831]

You must have changed the main battery, not (only) the start/stop battery (if a MY2010 car even has one)? A fully charged battery connected then the wrong way? You need to check pre-fuses too. Lucky if only fuses gone.

And yes, the whole thing with fuses and relays etc. is the rear-SAM.

Yea brand new agm battery
Have proper voltage at pre fuses and no fuses blown in engine or boot.
Car wont start turns np tho.
scanner telling me rear sam problem and when erase fault it goes then when try to start comes back on

 

[Uptnorth]

Car was laying over winter and battery died.
Bought new start/stop battery.
Connected to the wrong terminals for about 5 secs.
Car wont start now and getting the below fault.
Checked voltage at pre fuse box all ok
Checked all fuses beside brake fluid all ok
Also checked fuses in boot all ok.
Dont seam to have a fuse box at side of dash
Any help on where i should be looking next


View attachment 136472

Could the auxiliary battery have been affected as this controls some of the items in the display radio etc . Just a thought.

 

[richard]

If you look at the jump start point, it is in fact a fusebox with some very large fuses in it. Check those. You will be very lucky if its just a fuse :-(

There looks like some dodgy stuff going on with a red wire in the rear fusebox that been connected to a relay connector without a fuse (and ignoring the fact that its likely to get worn through on the metal bracket, and then melt and possibly catch fire)

You're probably going to need Xentry Diagnosis to work out what the error codes really are ..

R

 

[paul831]

If you look at the jump start point, it is in fact a fusebox with some very large fuses in it. Check those. You will be very lucky if its just a fuse :-(

There looks like some dodgy stuff going on with a red wire in the rear fusebox that been connected to a relay connector without a fuse (and ignoring the fact that its likely to get worn through on the metal bracket, and then melt and possibly catch fire)

You're probably going to need Xentry Diagnosis to work out what the error codes really are ..

R

I traced that to find out what it is, its how the reverse camera was fitted must be aftermarket

Checked at jump point and all fuses fine.

Is rear sam coded ?

 

[richard]

Yes, rear sam is coded.

Please add a 5A fuse to that red wire - whoever fitted it didn't understand electrics. Didn't even have a crimper to put a round contact to fit on the earth bolt :-(

 

[richard]

Theres also a whole load of non-original fuses in that fusebox, did you replace them ?

 

[paul831]

Yes, rear sam is coded.

Please add a 5A fuse to that red wire - whoever fitted it didn't understand electrics. Didn't even have a crimper to put a round contact to fit on the earth bolt :-(

What year did they code SAM from i was reading it was only coded in later modules.

I can tidy them up when im putting new one in

 

[paul831]

Theres also a whole load of non-original fuses in that fusebox, did you replace them ?

Nah but tested them all and all working

 

[richard]

They are always coded on W204 for the options on the car. I'd get a fuse map out (or look on eBay at a used one!!) and check the fuses are the correct value, I think that red one at the bottom may be wrong value, and that's the one that powers the rear SAM internal electronics !! (i.e, check it really is good before replacing the SAM if you can't talk to the SAM with diagnostics machine)

 

[alexanderfoti]

The code you have indicates internal damage in the rear Sam.

Rear Sam is the whole model, Inc fuses etc.

You have no start as you have no power to the fuel pump, which is fed by the rear fuse box.

Its coded for the options, but not vin coded, so a used one will need to programmed and may not work correctly without coding

 

[paul831]

Cars up and running cheers for the help folks

 

[Ted]

Cars up and running cheers for the help folks

That’s good news
What did you do to fix it?

 

[paul831]

theres a relay in the rear sam that controls fuel pump

 

[BigJase88]

theres a relay in the rear sam that controls fuel pump

In theory reverse polarity on a relay would not cause it to fail as it is just a coil so polarity is not really important.

Maybe was just gubbed anyways