Troubleshoot Engine Codes

[Yoda]

Originally Posted by CTScott

It does sound like a bad ground or bad connection in general. Have you checked the terminals on the two large connectors of the positive battery terminal for corrosion(under the back of the terminal)?

Also, check the ground straps that go from the negative terminal to the engine.

If all of that looks OK, try measuring the battery voltage at various locations around the car (at the battery, in the fuse panel, at the dash power outlet, etc.

If that looks OK, I would pop the ECM out and pop off its cover to see if there is any visible damage.

I am not that savvy with electrical stuff so this may seem like a simple question. How do I measuring the battery voltage at all those spots? I am assuming I am using a multimeter but apart from that total noob mode.

[CTScott]

Originally Posted by Yoda

I am not that savvy with electrical stuff so this may seem like a simple question. How do I measuring the battery voltage at all those spots? I am assuming I am using a multimeter but apart from that total noob mode.

Multimeter set to DC voltage mode (and range set to 20 volt range if it is a manual range type). Put the positive (red lead) on the item to measure and the negative (black lead) on a ground point (bare metal under the dash, unpainted bolt head {if the bolt is screwed into metal}, or a white wire with a black stripe on any connector {white/black is always ground on the Yaris}.