Hi guys,

Well, I just picked myself up a 3rd gen and I am in full learning mode now trying to get myself up to speed with all this 3rd gen stuff that is fairly new to me.

I picked up an 03 3500 QC 4x4 w/6spd. This thing has a couple of codes that I need a little help with and I was hoping you guys may have some experience with them so, here goes:

P0628 - "Fuel pump circuit low"....I take it this is the LP? It has had the in-tank conversion done. Is this referring to low voltage going to the pump? Possible causes? Help?!

P0633 - "Immobilizer key not programmed".....Seems self-explanatory....I guess it has to be reprogrammed by the dealer with a DRB style tool?

P2607 - "Air heater "B" circuit low"....Is this again implying low voltage? I take it the A and B circuits refer to the 2 different grid heater solenoids? Is this actual grid heater voltage or the voltage for the solenoid trigger wire? Would seem to me that both solenoids would be triggered by the same circuit from the PCM? I just have no clue! FWIW, the grid heaters "appear" to be functioning properly.

Any help yall could provide would be appreciated!

Thanks guys...

 

May be bad grounds / connections , in DC voltage , low volts is most often bad /partial ground , no power is bad Pos connection .
With computers in trucks / cars , this is the number one thing that kills the computers - bad grounds .
Start at batteries = load test , Alt load test , connection to both of those , then move to body grounds mainly to computer .

 

Ok, I'll start checking grounds. Are there any troublesome ground locations that are known culprits?

 

Just saw an other post , that looks to be a regular problem .https://www.dieseltruckresource.com/...ad.php?t=81936