I have a 2003 cummins and im having a starting issue. Runs great when started when warm it starts all the time. it all started with a low voltage to ecm code so i changed the batts and cleaned up all grounds. Now my truck wont start in the cold unless I plug in the block heater. Any ideas how to troubleshoot this or where I could start?
Been reading that it could be a few things.
The ignition switch could be failing and not telling the engine to start.
It could be your grid heaters are not coming on. (fuse) When you turn your key on does the wait to start grid heater coil come on?
Some people have had bad injector(s) bleeding back to the return and the cp3 can't keep up when it is cranking slow.
Your fuel filter might need changing. Could be an IAT sensor.
Turn the ignition key on - off -on - off -on leave it on but don't start it.
Your odometer should list any trouble codes.
Right them down.
Try reposting in the following section your original post and what, if anything, you have found out
3rd Gen. Powertrain - Dodge Cummins Diesel Forum