Low volts

[Unocam]

Hello everyone i had a question that i can not find concerning my hondata s300 v2. My issues is according to smanager my battery is showing anywhere from 3 to 7 volts, from my battery i read 13 volts on my multimeter. I just had the battery and the alternator tested both are good. I also checked my grounds i have a total of 4 now. This issue is causing my car to just want to just die it might idle at less then 1000 rpms. And run really rich according to my wideband. Please help me id really appreciate the help.

[Spunkster]

Have you used a multimeter to check the voltage at the ECU pins?

[Unocam]

Yeah it reads 12.4 on pin a25. I have a video of the smanager showing the battery voltage going crazy.

[Unocam]

https://youtu.be/wlnPXGMT2Ik

[Spunkster]

Can you post the calibration used as well as a datalog showing the issue.

[Unocam]

https://www.hondata.com/forum/download/ ... 4486252022


https://www.hondata.com/forum/download/ ... 4486252022

[Unocam]

I also just put the ecu in another car with a stock p28 calibration and got the same low voltage at 7.9 volts on smanager. Could the ecu board itself gone bad?

[Spunkster]

You should try your s300 in a different ECU to see if it is the ECU that is the problem. Also is J12 cut on the ECU?

[Unocam]

That is my next step is to try another ecu. And yes j12 is removed. Thank you for all your help

[Unocam]

Final update i replaced the ecu and had my s300 implanted in a new p28 and its fixed now i guess a capacitor or something went bad. They are 20 year old ecus