[bmwm3power]

Hey guys,

today i had a 318i cab n42 that won't start. So i tryed to read error codes with ista 4.46 and genuine icom next.
It can't read out vin. When i type vin maually all the ecu's are red. With inpa no connection to a single ecu.
All the electronics seems to be ok. All lights are on.


What i done until now:
-checked fuses
-battery reset
-another instrument cluster and GM
-disconected EWS, IHKA, Radio, DME,GM and LCM
-check voltage on pin 7 at obd2 (12v)

All with the same result. Any ideas?

[Node]

Have you done ANY diagnosis before parts cannon? Like checking that pin8 is not shorted to 12V, etc... Sounds like some unit is shorting it.

[bmwm3power]

Have you done ANY diagnosis before parts cannon? Like checking that pin8 is not shorted to 12V, etc... Sounds like some unit is shorting it.

Yes, the first thing i done was try to read error codes with Ista.
How i can find out if the dbus shortet to 12v? Because this bus ist working with 12v.

[Node]

Best way is to look at the signals using oscilloscope. In the worst case you can try to measure resistance between it and +12V or try to pull it to ground via some kind of resistor/bulb.

[Liteace]

It should not have 12v on pin 8 of 16 pin obd2 socket, pin 8 is K-line, does it have round under-bonnet 20 pin socket, if so try from there

[bmchicago]

have you tried using EOBD reader to see if you can communicate with DME through PIN 7?

Usually TXD1 line taken down by LWS(Steering angle sensor) or Xenon headlight.

[bmwm3power]

There is no 20pin connector on n42 engine. Only 16 pin.
I read DME with Bosch KTS and this worked.

Tomorrow i will try diconnect xenon and LWS.


...and sorry i mean pin 7 not 8. There is 12V on pin 7 !!!

[Vojno]

and pin 8?
The d-can interface has direct wire between 7 and 8!
This means that neither powertrain (PT_CAN) nor chasis (K_BUS) can't work the diagnosis (car is totaly dead diagnosis) if one of them is short-circuited!
If you separate this two wire then you can decide the DME ot the KOMBI has wrong diagnostic line!
The KTS maybe read only pin7 on which DME/DDE and EGS is available only.
On E46 KOMBI breakdowns are common.

[bmwm3power]

Today i disconnected LWS and this is the result. I think IKE is broken. In DME is a error interface between EWS and DME. The EWS say key is invalid. I thin i try a new key from BMW.

[crazybm]

Today i disconnected LWS and this is the result. I think IKE is broken. In DME is a error interface between EWS and DME. The EWS say key is invalid. I thin i try a new key from BMW.

No.
IKE is not broken. You have a problem with the diagnostic bus.
IKE is the gateway, so if it's broken you wouldn't have any comms with any CU. 
I looked in car VO, vehicle has xenon. disconnect both headlights and retest. other components in the diagnosis bus is the steering angle sensor, rollover sensor (it's a cabrio) , and DSC but you tried that already. disconnect these if Xenon doesn't reestablish comms.

Look in your diagnosis bus wiring diagram in case your car has other components in the Dx bus.