NEED HELP RS4 B7 BDM READ

[volksdude]

Hi,

to make a long story short we got that b7 rs4 for dirt cheap bc it was a poorly maintained car and it needed a lot of repair so me and my buddy tought we had a great oportunity to get a quarantine project that was cool.

so car don't start and with VCDS I have no communication with ECU1 whatsoever, I do get something with ECU2 Showing but crashes. If I unplug ANY of the ecu I can get ECU2 to log in and work

we bought 2 used ecu's to replace. car was starting and stalling ( immo) so I read both original ecu's with bdm and flashed the new ones basically cloning them

but now issue is the very same as with the original ecu

can someone tell me if something is wrong with those reads?

[volksdude]

I did a few tests and I can communicate with ecu2 whenever only 1 ecu is plugged regardless of master\slave position if it can ring anyone's bell and help me out here

when i communicate here are the codes that always pops

049408 - No Communication with Engine Control Module (SAE ECM/PCM)
U0100 - 008 -
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 217608 km
Time Indication: 0


Freeze Frame:
RPM: 0 /min
Load: 0.0 %
Speed: 0.0 km/h
Temperature: 143.0°C
Temperature: -40.0°C
Absolute Pres.: 0.0 mbar
Voltage: 11.938 V


006436 - Controller Pin Coding
P1924 - 008 - Implausible Signal
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 217608 km
Time Indication: 0


Freeze Frame:
RPM: 0 /min
Load: 0.0 %
Speed: 0.0 km/h
Temperature: 143.0°C
Temperature: -40.0°C
Absolute Pres.: 0.0 mbar
Voltage: 11.938 V

[volksdude]

could someone just tell me wich pin in ecu receive voltage to determine master ecu?

[skolotoi]

RS4/R8 2xMED9.1 Master/Slave config:

T94/36 on connection D141 (+5V from T94/19) blue/red : Master (Add. 01)

T94a/36 on connection 121 (ground) brown : Slave (Add. 11)

Look also page 12 and 17 in the attached .pdf


P.S: You know your "OLD" ecus are "UNITRONIC CHIPPED" ?

[volksdude]

Thanks a lot that will help me continue my quest.

As for unitronic chipped ecu's yeah I found out last week

[volksdude]

For those who would like to know what my issue was: It wasn't flash related at all, my initial cloning was good all along. like skolotoi pointed I checked the 5v circuit going to each sensor to find out that low fuel pressure sensor G410 was shorted. as soon as I was plugging that sensor, voltage went from 4.96 volt to 0.08v.

Hope that it will help someone else that might run into the same issue