Quote:
Originally Posted by lariat 7.3
po603 and i had one that was like po440 or something. what do they mean?
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The P0603 relates to a PCM "KAM" error (KAM= "Keep Alive Memory"). This DTC can show up when the battery voltage is low or not present. Did you recently have the batteries unhooked for any reason, or did they get low or go dead?
This code can also be set if the PCM was removed from the truck (again, a no power situation). Also, if it was removed, and possibly during reinstallation, one of the power pins may have been damaged or is not making good contact with the PCM connector: double check your connector, if so.
It could also be a blown fuse in the "KAPWR" ("Keep Alive Power") circuit. Depending on your model-year, this fuse may be located in the fuse-box under the dash, fuse #15 (5 amp). This fuse also supplies power to other things (like the GEM module, 4-wheel antilock, etc.), so those other things may not be getting power as well.
Lastly, the PCM may be experiencing some other internal memory failure issue...meaning the PCM may be bad.
The P0440 has to do with evaporative emmision controls, something you don't have on your diesel-powered truck! Are you sure it was a P0440? You might want to double-check on that one.
By the way, with DTC codes, those are numbers (zeros), not letter o's.
If you can clear the codes (or have them cleared) do it. Then drive awhile and see if they return. Or...they may also go away on their own, after a few drive cycles.
Good luck!
Quote:
Originally Posted by woodnthings8
PO603 means you probably have a tuner and you changed programming, When you do this it cycles power to the PCM.
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FYI: Power is not "cycled" to the PCM when changing tunes. At least not in the "Keep Alive" circuit. The KAM power is supplied directly from the batteries to the PCM (through a fuse, of course). Even with tuners that up-load through the OBD-II connector, the power is never interrupted. However, with some tuners, if/when a new program is uploaded to the PCM, it erases/downloads the original program, which can often cause a memory processing error and result in a "KAM error" DTC, even though the power was never actually interrupted.
