[USB Comms failed, RS232 voltages seem odd]

The Link USB COM port is showing properly with no yellow exclamation marks. I have tried with 2 different laptops (Windows 7 and Windows 8) and with 2 different comms cables and still no joy.

An attempted fimware update returns the message: Error, could not connect to ECU and then provides various troubleshooting steps which I have already carried out.

[USB Comms failed, RS232 voltages seem odd]

Thanks for the response.

I have unplugged it from the board. There is nothing connected to either CAN1 or CAN2 at the moment.

Will fixing this require sending the ECU back?

[USB Comms failed, RS232 voltages seem odd]

19 minutes ago, TechDave said:

RS232 is present on the CAN 1 port, this is the same RS232 that the micro chats with the USB.

As a quick test, unplug CAN 1 or switch to CAN2 (no RS232)

 

Hi Dave,

CAN 1 was unplugged as mentioned in the original post.

[USB Comms failed, RS232 voltages seem odd]

ECU is a PnP WRX104+. USB communication was fine at first. Today I tried to reconnect to the ECU but I'm unable to. The PC Link USB connection is seen but I can't connect to the ECU.

Between the last connection and now, the wiring loom has had some changes to it to remove extra wires and a CAN connector was also added to the CAN1 port.

I have removed the CAN connector since I've read that it can cause problems. The ECU is fine and still runs the car.

However while troubleshooting I noticed that RS232-TX has a steady -11V on it (yes, that's negative). Could this be the problem and does anyone have any ideas on how to resolve this?