No connection to EAT & BCU ECU on Discovery 2

TheSpitfire

New member
Feb 17, 2017
2
0
Sweden
Hi Forum,

My name is Marcus and just new member in this forum, happily driving a Disco 2 V8 from 2000 in Sweden.

I have tried to search here and the web for advice but not found the solution yet. I have an Disco 2 issue and now reaching out on the international forums for help after trying my domestic forum in Sweden first for a while. ( for reference http://slrk.egetforum.se/felsoka-obd-nanocom-ingen-kontakt-med-ecu-t22313.html )

I have a Discovery 2 V8 from 2000 that I'm not able to hook up with my Nanocom ( latest version). I have back tracked the K-wires (signal to all and each ECU) from the diagnostic socket to the connection point C0286 where the signal wires from all ECU's are gathered. There I can measure quite good signal streanght 9-10 volt on ECO for Engine, ACE, ABS, Airbag and Cruise control. But on transmission (EAT) ECU I get 0 volt and on body control unit (BCU) ECU i get a low 0.2 volt. When they are all connected to the single K-wire to ODB socket I get just below 2 volt consolidated signal. So the transmission and body control K-wire bring down signal strenght significant. In this situation the Nanocom cannot connect to any of the ECU's. It is not just low output but almost feel like a earth error on thos K-wires (but no connection can be measured to earth)

When I manually disconnect transmission and BCU ECU from C0286 I can at least connect to the ABS ECU and work on that one, but no connection to ACE etc. They seem dependent on the BCU ECU to work.

I have now also measured and ensured there is no cable break on the K-wire from the EAT and BCU ECU's itself to the Diagnostic socket.

Both ECU's for transmission and body control are working (as it seems) but just no output on K-wire.

Hope to get some input from the forum expertise how to continue error searching. Seems like to large step to change the ECU's at this stage as they seem to work otherwise.

PS. Car is working but would like to get this to work to handle future errors as well as read why my ACE is not working at the moment DS:
 

KyleT

Well-known member
Mar 28, 2007
6,059
8
39
Fort Worth, TEXAS
Sounds like one of the wires has corrosion at a splice joint or is pinched. Or the trans ecu has corrosion internally as it's under the drivers seat.
 

TheSpitfire

New member
Feb 17, 2017
2
0
Sweden
Did some more error search and took out the EAT and BCu ECU's. Could not see any corrosion on the EAT ECU but found some small "corrosion" on the BCU. Cleaned the BCU and now I can connect to that one.

Small intermediate victory!

Now I can connect with the Nanocom to the BCU and SLABS ECU's but the others are not accessable. I will try to take those others out for cleaning as well. I have found and ordered a used EAT ECU from Ebay so will see if that is the problem as a starter.