W238 - 2018 - no crank after crash

**bursuc** · 15th October, 2019, 09:31 PM

Hi all DK friends

I have a situation here. Car is Mercedes E300 petrol 2018 w238

Auction buy. Do the diagnostic on the car, i enable the starting after crash on engine ecu and even did scn coding on engine ecu because starter motor did not actuate even after.

I check "drive authorizition " in all ecu"s and did a FBS 4 TEST along with the key test. All is ok.

I test starter motor terminal on actual values on engine ecu and is switchin on and off when i press brake pedal and start button.
Both of starter relay wires are going straight into ecu ( MED 17.2.2 )

If i activate starter motor relay manually in same time somebody is pressing starting button, car start for 4 seconds and switching off....
Ocassioanly i get this fault in engine ecu

P051200 START RELEASE FAULTY

I lock/unlock the car with remote key and this fault code sometimes goes off but still not starting

I put some pictures with positive relay box or whatever it is. On the side with the battery i have +12 but the other side i dont have.
There is a plug with 3 pins ( only 2 are used - gnd terminal 50 ) data pin is unused. Before i put termina 50 to positive starter motor was working when activating relay but no is onli clicking ( only starter motor coil ) i had to take big cable from this fuse/relay box and attach it to a + 12 positive and now is cranking again but still not starting
I think i must be burn it ... but problem is still at square 1

Any ideeas would be very appreciated!

**Meat-Head** · 15th October, 2019, 09:39 PM

Is there anything in srs for crash data

**bursuc** · 15th October, 2019, 09:49 PM

Yes. SRS is full of crash data . and in actual values , CRASH is detected. Prior 2018 - i did not have to do anything in SRS and cars were starting .... this is 2018 and it looks to me something has been added in order to make it harder to start it

Also - front bumer is missing totally along with RADAR module. there is no RADAR module on the car

**Meat-Head** · 15th October, 2019, 10:54 PM

Ok, not sure on model we had some Mercedes in for a towbar. In the trunk
RIGHT in the corner rear right was a small battery

if you put your jumper cables in, would hit it, have a look see if has flat second battery

**bursuc** · 16th October, 2019, 02:29 PM

I also did SCN on engine ecu? Do i need to do on airbag ecu aswell?
Regards to the second battery i could not fiind one in the boot

BR

**Meat-Head** · 16th October, 2019, 07:27 PM

No idea then. If your in UK I got pished off with a Mercedes, no answer with
uk hq, rung the breakdown line to moan, didnt help, but got great load of info