Nanocom - unable to init communication with ECU

[duncanw]

I've got the latest USB model nanocom and it's having problems talking to the ecu on a 2003 defender.

I've tried the following


reloaded the 2.03 firmware
turned the ignition on, off, engine running and engine off
disconnected the electronic rust protector (apparently it can cause interferance)
checked the yellow cable is wired up correctly as per the FAQ page
did a test on the odb port with the display as

01H 02H I1H I2H testing pins 4-5 and 8 I get 10v
01L 02H I1L I2H testing pins 4-5 and 8 I get zero volts (as expected)
01H 02L I1H I2L testing pins 4-5 and 8 I get 10v (not expected, should be zero volts)


Can someone please run the obd test on theirs and tell me if you get the same results ? I am thinking that the high / low logic that the nanocom uses to transfer data between the ecu and the nanocom isn't working so this is why it cannot init the communication with the ecu.

Thanks

Duncan

[Tusker]

Not being flippant, but did you turn it on? There's no on/off switch per se.

With the engine running, if you previously hit the lh button, try pulling the cable & reconnecting

Or if you just plugged the cable in when running before, then try hitting the lh button.

I find the yellow cable doesn't always connect properly as well.

Regards
Max P

[duncanw]

Not being flippant, but did you turn it on? There's no on/off switch per se.

that thought has gone through my mind a few times :eek:

I've thought along the same path and tried a few different variations, plugged in before I turn ign. on, plugged in after ign. on, plugged before and after engine on.

Same result in the end.

[duncanw]

ok I've got it working now, if anyone has the same problem here is what I did to fix it.

The yellow cable was wired up wrong, pins 7 and 8 need to be reversed, to test if you need to reverse them run the odb test

01L 02H I1L I2H testing pins 4-5 and 7 expect zero volts
01H 02L I1H I2L testing pins 4-5 and 8 expect zero volts

Please note this is different to what is on the nanocom FAQ, I have emailed nanocom to let them know the data on the website is incorrect.

I worked this out after we pulled the ecu and abs out to check the ground connections like what is suggested on the FAQ:(

[jmkoffice]

ok I've got it working now, if anyone has the same problem here is what I did to fix it.

The yellow cable was wired up wrong, pins 7 and 8 need to be reversed, to test if you need to reverse them run the odb test

01L 02H I1L I2H testing pins 4-5 and 7 expect zero volts
01H 02L I1H I2L testing pins 4-5 and 8 expect zero volts

Please note this is different to what is on the nanocom FAQ, I have emailed nanocom to let them know the data on the website is incorrect.

I worked this out after we pulled the ecu and abs out to check the ground connections like what is suggested on the FAQ:(
Can you be alsolutely sure it's not a specific wiring reversal on your vehicle only? To elimate this possibility, another vehicle the same as yours needs to be tested. Maybe Nanocom are wrong, this has occured before.

[duncanw]

I'm 100% sure it's not the vehicle. I have the wiring diagram for the Defender and I was tracing the wires back to where they hook up to the ECU-ABS and the main ECU, and it matches as per the wiring diagram so I hope it's correct !

I then put a multimeter on the pin which was supposed to goto the ecu while I was trying to get some data back from the ECU and I noticed that the voltage on the wrong pin was fluctating, this is how it tranfers the data so I resoldered the yellow wire to reverse pins 7 and 8 and it worked.