MSefi.com read only forum (Jan.15,2018)

Hi, I've done some mods on my board and I'm using the two +5V holes and the two ground holes on the proto area.

While I was doing some continuity tests to verify my modifications, I've discover that there is some continuity between +5V and ground on the proto area. Here are the results I obtained :

+ lead on +5V, - lead on ground hole = 700 ohms continuity
- lead on +5V, + lead on ground hole = 440 ohms continuity

So, is this normal? In my primitive understanding of electricity, there shouldn't be any continuity between them unless there is a kind of power draw. This test was done with the Main board only, no external wiring and ECU chip removed.

Let me know!

Sam

Sam,

If you have some device that has 400-700 Ohms resistance connected across from 5V to ground, then you will show some continuity. Any device needs to be connected between power and ground, and any device has a some degree of resistance.

400 Ohms is only going to flow 5/400 = 12.5 milliamps, a very small amount of power that is unlikely to fry anything. It may be the CAN termination resistor, or any of the chips on the board, or...

So what I would do, instead of measuring the resistance, is power up the board and make sure there is a full 5 Volts (±0.1V) between the 5V side and ground, then you should be good to go!

Lance.

Ok, that is more clear now.

I'll check for the +5V when the ECU is powered.

Thanks for the tip!

Sam