Hello everyone. I'm working on a Cat P5000 and no start when cold , engine runs fine when using B12 to start. So far I've replaced the injector holder with everything already assembled , including new injector. I checked voltage at the injector plug while turning over engine and got 3 volts going to the injector , from what I read the injector needs 10.5 volts for a rich condition to start. I pulled the plugs from the injector driver and the ECM and found the pulses from the cam and crank sensors , so I know they both work. I checked the voltage coming out of the driver unit and still the same voltage , 3 volts. At this point fingers are pointing at the injector driver. If anyone has anymore info on the principles of operation for the starting system , between the ECM and the injector driver please let me know. Thanks in advance.