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Paul Mugabi

USB Comms failed, RS232 voltages seem odd

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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?

 

 

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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.

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20 hours ago, Paul Mugabi said:

I have removed the CAN connector since I've read that it can cause problems.

Have you actually unplugged it from the ECU board, or outside the ECU case?

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In windows device manager, is the ECU showing up in the COM ports section with no yellow exclamation marks or anything?  What happens if you try to do a firmware update in PC Link, does it still not connect?

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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.

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Ok, unfortunately it is sounding very much like you have a hardware issue.  It seemed like too much of a coincidence at first that it lost USB comms when you were messing around with CAN1, but it sounds like you have ruled out all possible interactions there now and covered all other troubleshooting steps that would normally be requested.  It is pretty rare for a hardware issue on the USB side but I cant think of any other explanation that is more likely.  I suggest you email tech@linkecu.com and get their advice on getting it inspected.  I dont know where you are in the world but it will likely need to go back to NZ.  

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