No Answer from ECU; Error: 204; Function: DownloadFile"

[NickFro]

When trying to download a new file to the ECU, I get an error message after about 3 seconds that says "No Answer from ECU; Error: 204; Function: DownloadFile".  The controller seems to be functioning properly otherwise.  The existing file stays loaded after failing to download the new file.  I have a number of different files that I know are good, and have tried multiple times.  Is the controller toast, or is there something else I can do?

[Jakob]

Hi NickFro

The first thing I would check is the wiring.
   Resistance 60 ohm total, and all that.
   Controller outputs being overloaded or disrupting the controller.

Next, are there any other controllers connected?
   Conflicting nodes for example.

Third, are there any changes in the programs CAN-bus setup?
  Node, baudrate and so on.

I'm sure somebody has a few more things to look for, but I in my book those are the places to start.
If it is a new controller, it is unlikely that it is toast. But never say never.

Have you tried the same program with another controller?

I hope this helps
BR Jakob

[NickFro]

Someone had switched the CAN BUS wires on me.  Should have looked at that first.  Thanks.

[Jakob]

Your welcome

[Ascorige]

Isn't this a also symptom of a controller with a faulty CAN system?

[Kelly]

Just ran across this "Error 204" problem with a service tech in the field trying to program display and microcontroller to newer program revisions. Not much info I could find on the internet/forum other than this thread from 2013, so this is a good place to standardize potentially helpful information.

Details:
- Service tech was using Service Tool v5.1 on a pretty old (Windows XP) laptop
- He could see everything fine when connecting to the CANbus
- Programs that he was attempting to program to ECUs were composed/complied in GUIDE v6.1 (and original revisions all the way back to even earlier versions)
- Programs written to ECUs at 250k baud rate wrote fine/correctly (for example a brand new "blank" DP610 from Sauer)
- Programs written to ECUs at 50k baud rate (the CANbus baud rate our machines use) would time out within 3-5 seconds and dialog "Error 204" would come up. Could never successfully program ECUs @ 50k baud rate - never had any other issues like this related to 50k baud rate.

After consulting with our local PLUS+1 controls group support personnel, my service tech updated Service Tool to v7.0 (current version), and problem went away, ECUs could be written to properly, etc.

Success.

-Kelly