Hello,
I have this WAVE with service code 136 active.
The possible causes are:
- Unexpected failure of controller software. Try to restart (power up) again
- Open or short circuit on communication lines
- Short circuit to battery positive on communication lines
- Display or controller Failure

I have check the wiring for short or open circuits and everything is OK. Obviously I tried to restart the machine but the problem remains.

It seems that the problem is inside the Controller or Display.
I have opened both of them and I didn't find any visible signs of malfunction.

Is there something else that could cause this error?
What does usually happen with the Controller or Display with this service code?

Thanks!