Log shows battery voltage 0.1v max

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mooney
MS/Extra Newbie
Posts: 25
Joined: Fri Apr 26, 2013 7:00 pm

Log shows battery voltage 0.1v max

Post by mooney »

A friend purchased an MS1 V2.2 ecu used. We installed an MS2 daughterboard, loaded firmware, then wired it up in the car to try it for the first time . It cranks but does not start.

Looking at the log while cranking shows no RPM signal and thus no PW (things we will need to look into with regard to the EDIS-4 VR sensor and wiring.) more bothersome though, is that the log shows 0.1v min and 0.1v max for battery voltage .

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Changing the power source for the controller does not make any difference.

Unsure where to start, I took a peek inside for anything obviously amiss. I see a small burn mark on a tantalum capacitor.

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This could have been from a poorly placed soldering iron by the person who owned the ecu last, but it may also be a bad capacitor, so I replaced it. I had hopes this would resolve the 0.1v battery voltage since the capacitor goes to the voltage regulator and figured it may have some relation.

No change.

I know the controller is getting some sort of voltage since it connects to the laptop and processes sensor inputs.

Thoughts?
1991 BMW 325i
slow_hemi6
Super MS/Extra'er
Posts: 4122
Joined: Fri May 07, 2004 3:33 am
Location: Australia

Re: Log shows battery voltage 0.1v max

Post by slow_hemi6 »

Measure the voltage across the mainboard boot jumper pins. Should be about 2V or 1/6 supply voltage.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
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