The signal (in my'01) is generated by the ECM. It sends the PRIME command prior to starting. It then sends continuous RUN command while engine is running.
I lost my signal 5 years ago. It was NOT fuse-related. There simply was no emission signal. It then caused the DREADED P0215 code (injector pump malfunction); which cost me $1500.00 to replace the injector pump.
What I did to fix was to:
1. Get rid of the engine-mounted Carter lift-pump. I installed an engine-mounted Bully-Dog lift pump in its place.
2. A MUST HAVE FOR INJECTOR PUMP PROTECTION:
Installed a lift-pump pressure gauge from Westberg (an avionics company), via Genos Garage. There are two sender-types. Get the one for DIESEL FUEL (yes, it is more $$$). The other leaks and fails when exposed to diesel fuel, within 6 months, as originally included in the kit. I had to LEARN that. Luckily, Westberg is in my backyard and I was able to upgrade with little effort. I notified Genos of the issue but unknown if it has ever been resolved. The lift-pump FP gauge will let you know if there is a potential issue with the the fuel pressure, which could damage the injector pump. Damage typically occurs with <5psi. Nominal running PSI for me is 15 when idling // 9-12 cruising at 70mph // 7-9 WO.
3. I BYPASSED the ECM and am running strait off of +12Vdc coming from my "Key-ON" section of the fuse-block. It has never caused me any issues.
What I would LIKE TO UPGRADE:
Remove my Bully-Dog (engine-mounted lift-pump) and go to as rear-mounted FASS. All engine-mounted lift pumps are SUCTION systems. That also means that if there is an air-leak somewhere, it will suck in the air (like a hole in a soda straw), which will decrease FP and decrease performance. The FASS is a pusher system, mounted on the frame near the tank. If there is an air leak, the POS pressure in the line will not allow it in....you'd likely notice it, with potential expulsion of dripping diesel-fuel, since now the line is charged, rather than sucked upon. Plus, the FASS (and likely similar rear-mounted systems) will have a built in air-separator and water seperator in the back. They further tout that the fuel is continuously polished while in service.
So I have a 1999 Ram 2500 5.9L Thick 53 block, mods are phatshaft turbo s&c intake shroud, Afe filter, banks high ram, ppump, fass titanium fuel pump, all gauged, pyro1, boost, trans and fuel. Problem: some days when its chilly I will start her she will spin up just fine but be sputtering and coughing at about 10-13 fuel psi, white smoke for a bit. if I pop the throttle it will jump to 17 psi and be just fine this will persist till I do that. if I through it in R she will either sputter and die or sputter and chug along. I am lost, Currently waiting to get a new Draw straw. Any help that can be given would be greatly appreciated.