Micro rusefi battery sense is faulting out

[Kawasakik1e]

DIY motorcycle project Kawasaki KZ650 conversion to efi.
My issue is the #1 Battery Sense wire faults out ("Fatal" LED lights up on the board and disconnects from Tunerstudio) when Connected to positive battery power, whether straight off battery or at the main relay. Having this issue wether my laptop is connected or not....
Also, at the same time the #29 main relay low-side wire is not actuating the main relay. Previously it was switching on the relay( relay still works; I currently have it wired it to ground).
I'm still in the learning process; I had updated the Firmware a couple days ago..... not sure if this has something to do with it?
Unit is micro usefi R0.5.3

[AndreyB]

A lot of important details are missing. If you suspect firmware please go back to older version.

[Kawasakik1e]

Yes, newbie here... my apologies but thanks for the response
I have reinstalled the .f4 firmware.... i believe there are only 2 versions of firmware for the Micro rusefi; .f4 and .f7
A long distance friend told me I need to use .f4 based on "f4" printed on 1 of the 2 bigger chips on my board...
...so, with only the positive and ground power wires connected to ecu (wire harness disconnected and ecu on workbench) as soon as I connect the #1 Battery Sense to battery positive, the ecu lights upthe "FATAL" LED on board.
Also, when Connected to tuner studio- with only battery positive and ground, the voltage shows as 2.6V before connecting #1 Battery Sense wire to positive battery. When #1 is connected to positive battery power, guage will display battery voltage, as in "12.3v" but needle doesn't move and board faults out immediately.
One other clue; my #29 main relay low-side wire was previously working to acuate the main relay- now it's not working.
Wondering if my board is damaged....?

[AndreyB]

the ecu lights up the "FATAL" LED on board.

Does blue LED blink? If FATAL LED is turned on TS would have an error message?

[Kawasakik1e]

Yes, the blue "COM5" light is blinking and when Connected to laptop with USB cable, my wire harness is functional- spark, injectors, tps etc- communicating with tunerstudio. When #1 Battery Sense is supplied with battery positive, all lights on board go out and "FATAL" LED lights up. When I am connected to laptop and this happens, Tunerstudio flashes "disconnected " I believe.... nothing else. I have to power off the ecu or hit "RESET", then Tunerstudio reconnects.


I appreciate any help or feedback AndreyB....!

To review:
*with #1 not connected, Tunerstudio is reading 2.6V WITH ALL SENSORS, INJECTORS AND COILS DISCONNECTED
* If I connect #1 to battery ground, Tunerstudio will read 0 volts
* when Connected to Tunerstudio and applying battery positive to #1, ecu faults out (FATAL) and Tunerstudio will read the correct battery voltage (12.6V example)AND disconnect.
*with ONLY the ecu powered-using #2 and #6 ground wires and #5 positive voltage- nothing else connected (no wire harness/sensors or laptop connection) and then connecting #1 Battery Sense to battery positive, the ecu faults out- "FATAL"
* AND oddly, the #29 main relay lowside trigger isn't functioning when wired in.... previously it did work/switch the relay on.

[AndreyB]

the ecu lights up the "FATAL" LED on board.

Does blue LED blink? If FATAL LED is turned on TS would have an error message?

Does blue LED blink once you get red "FATAL" LED on board?

[Kawasakik1e]

No, blue light goes out. Only the red "FATAL" light is left on.
Thanks for the response.

[AndreyB]

No, blue light goes out. Only the red "FATAL" light is left on.
Thanks for the response.

This could be an unknown software defect maybe similar to https://github.com/rusefi/rusefi/issues/6976 maybe totally unrelated.

Try resetting settings, try different release, try isolating which specific setting maybe triggers this probably firmware issue.