Audi Q7 3.0TDI ECU dead?

[razor1199]

Hi everyone,
I have problem with Audi Q7 3.0TDI 2007 year. ECU EDC16CP. Engine had just turn off, doesn't turn on again. All fuses are OK, relay 617 is also OK, terminals 30, 15, 31 on ECU are OK.
When ECU is connected to the car, I can't connect with ECU, ABS, Airbags, Transmission, and there are DTC's about communication with them in various modules. CAN Gateway can't reach those modules. After I unplug ECU from a car I can connect to everything (excepted ECU ofc.)
Can ECU be dead and send wrong signals through CAN?

[baze007]

in principle it is possible to disable the can network


Test ecu on bench

[rob h]

Happens often with low voltage.
Put in a descent battery, with good amperages!
Dont try to jump start.

Then erase dtc, and you should be good.

[razor1199]

I tried with good battery, no luck.
I tried to communicate with ECU using vagcom on bench via pinout, no success. Now ECU number is 4L0907401, I wonder if I can put another ECU for example from A6 3.0TDI 4F0907401C?

[baze007]

I tried with good battery, no luck.
I tried to communicate with ECU using vagcom on bench via pinout, no success. Now ECU number is 4L0907401, I wonder if I can put another ECU for example from A6 3.0TDI 4F0907401C?


copy all data from orginal to donor ecu and start car

[razor1199]

Somebody offered me this ECU from A6, I just want to know if it will work, cause numbers seems to be different, and there is "C" at the end.

[baze007]

Somebody offered me this ECU from A6, I just want to know if it will work, cause numbers seems to be different, and there is "C" at the end.


it will work

[razor1199]

Hey again, I still have problems with this Q7. Original ECU was completly damaged, capacitor has shooted, corrosion everywhere under air plug, after cleaning all of this I still couldn't do BDM reading, no respond from ECU.


I decided to buy new ECU with same numbers as original but with IMMO OFF. After I put new ECU to plugs CAN problems has been resolved, but one problem still exist.
I can't connect with ECU, gateway module list shows that 01 - Engine cannot be reached. Many modules, like Airbags, ABS, Instruments etc. shows error 01314 - Engine Control Module: No Communications.


Once again I have checked GND and supply voltage.
On the big plug (94-pin) there are:
pin 1 - GND OK
pin 2 - GND OK
pin 4 - GND OK
pin 3 - +12V after ignition ON OK
pin 5 - +12V after ignition ON OK
pin 6 - +12V after ignition ON OK
pin 18 - +12V after ignition ON OK


CAN lines hasn't any short, I have also checked CAN circuit from ECU to LEFT separating connector and also is OK. Main ECU relay -J317- is also OK.


Should be there any +12V on ECU without ingnition ON?
Maybe someone had same problem like me with connection to ECU?

[Aajii]

Hey again, I still have problems with this Q7. Original ECU was completly damaged, capacitor has shooted, corrosion everywhere under air plug, after cleaning all of this I still couldn't do BDM reading, no respond from ECU.


I decided to buy new ECU with same numbers as original but with IMMO OFF. After I put new ECU to plugs CAN problems has been resolved, but one problem still exist.
I can't connect with ECU, gateway module list shows that 01 - Engine cannot be reached. Many modules, like Airbags, ABS, Instruments etc. shows error 01314 - Engine Control Module: No Communications.


Once again I have checked GND and supply voltage.
On the big plug (94-pin) there are:
pin 1 - GND OK
pin 2 - GND OK
pin 4 - GND OK
pin 3 - +12V after ignition ON OK
pin 5 - +12V after ignition ON OK
pin 6 - +12V after ignition ON OK
pin 18 - +12V after ignition ON OK


CAN lines hasn't any short, I have also checked CAN circuit from ECU to LEFT separating connector and also is OK. Main ECU relay -J317- is also OK.


Should be there any +12V on ECU without ingnition ON?
Maybe someone had same problem like me with connection to ECU?


You can test ecu communication on the table. If it works you have problem in car. If it doesnt work on table, you have problem in ecu.

[razor1199]

I have connected new ECU again on the table and used VCDS to watch it, ofc no communication, I had another EDC16 and another works ok, so new ECU is dead :mad-new:

[garagesport]

Hello partner, I have the same problem but in my case I have communication with ECU and I have two ECU but the car does not start


I solve the problem can you help me thanks and regards