99 frreightliner N14+. 434 fault code. Cranks, no start.

Truck started fine this morning -20 temperature. Let warm up about 20 minutes. Got back in truck red engine light on. Shut truck off to do the self diagnostic. Code blinked out 434- is an open battery circuit. Tried to start truck again. Crank and crank but no start. Pulled filter fuel ok. no gelling or clouding. Checked cleaned all battery and starter connections. Cleaned ground posts on frame. Two little wires that are from positive battery post. One fuse was ok. The other was corroded so bad the plastic top of fuse came off the blades. I cleaned and changes fuse. The fuse up by ECM on ground wire was blown. I changed that. After this I tried again. The same fault code was coming up. However when I try to start, it almost will fire but not quite. It lopes.Seems like Its getting some fuel just not enough. I removed the return line, covered with thumb while cranking starter. I could not keep thumb on hose from pressure. I put that back together. Removed fuel filter and it was half empty. 434 fault code still comes up. Tomorrow I'm going to try to bypass the fuel line from tank to filter see if it will start. But that doesn't solve the 434 fault code. Thanks for any help.

 

During the time I was cleaning battery posts, the power was disconnected for about 30 minutes. Does the ECm have an internal battery. Thanks for the reply.

 

Yes the information is very helpful. When I pulled the ecm plugs off to check for corrosion and voltage. Found no voltage on pins from battery. Tomorrows task is to replace or bypass those lines in the harness to battery. Thanks.

 

pins 20-21-22-23. Unfused power feed from battery in actuator/injector harness. this supplies ECM with constant power. These four pins had no power.