hi guys, dad bought a 2009 ML320 CDI last friday and all was good. saturday we got up and car was dead. no lights on dash, nothing was working, not even central locking....battery was fully flat
we try to jump start if on terminals under bonnet and when putting second jump lead on it was sparking hard and then the starter motor was on...car was cranking but not turning on... even after pulling starter motor relay and fuse it was still doing it...all along still no dash light or any lights at all.

we thought maybe started got stuck so took it out (what an annoying job). after charging battery the dash lights etc came back on (starter is out of car at this stage).

so we put starter back in, and car starts as normal like nothing happened....

now we have a working car, BUT no wipers and also SRS light is on... spent a day today checking relays and fuses and all seems good but still cant get rid of those issues... says along lines of "front right malfunction" and ."restraint malfunction"

any advice would be much appreciated and what we could/should look at next... SAM module? is it the front or rear that controls SRS and wipers? thank you all

EDIT: just remembered, not sure if useful piece of info, but the little light next to hazard button for passenger airbag the light is lit showing OFF.

 

I don't know the answer to help you, sorry. In order to help you get an answer faster though, I would suggest posting the VIN number just in case that is needed for someone with more knowledge than me. Just want to save you the step of getting a reply asking for that and then waiting for an answer another hour or day after you post it. Good luck!

 

You must first low charge the battery overnight while the battery is disconnected and the voltage should read 12.7v.

When the battery voltage drops below 9 volts everything is shut down and many codes will be stored, two of which are the SRS and the wipers. You delete the codes for the SRS and wipers so the SRS light is removed and the wipers will again work.

A component, like lights, was left on when you turned off the ignition and drained the battery. Or there is a parasitic draw because of a component that remains on usually because of a faulty relay.

You must have your own scanner to read all the 25 modules in your vehicle.

Autel Scanner MD802 Maxidiag Elite Diagnoses

 

thanks for this. we did charge it (although not overnight) after we got it running again and battery seems to hold charge.

i have Autel diagnostic tool but am unable to clear the faults...just not coming up with anything. i did come across low voltage fault at ignition...

will try charge battery overnight as you suggested and try again see what happens...

any other suggestions are welcome

 

What are the codes and what module are they stored in?

 

UPDATE: fixed

today had dads friend auto electrician come over have a look at it. basically came down to 2 things...

1) battery.. (we got new one today)
2) a relay in the boot. grey relay in the "R" position. this is for Circuit 15R. relay was missing. now im not sure why that would cause issue cos SRS and wipers were working before but anyways... dad is happy its all running fine now...

thanks guys

 

Thanks