what do these DTC codes mean? - Diesel Forum

lariat 7.3 · 07-18-2009, 11:33 AM

po603 and i had one that was like po440 or something. what do they mean?

**woodnthings8** · 07-18-2009, 11:53 AM

PO603 means you probably have a tuner and you changed programming, When you do this it cycles power to the PCM.

Also uppdate your signature so others know what vehicle you may be asking about

Here are some code definitions
1999 Powertrain Control System Electronics Diagnostic Guide - 1994-1997 Power Stroke FAQ

calico5string · 07-18-2009, 02:34 PM

Quote:

Originally Posted by lariat 7.3

po603 and i had one that was like po440 or something. what do they mean?

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.

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.

PowerstrokeConverters · 07-18-2009, 02:43 PM

Ever since I used my first tuner, it gives me the KAM error, nothing bad though....just always shows up when reading DTC's.

lariat 7.3 · 07-18-2009, 02:52 PM

so when i changed it from performance tune to tow tune it deleted then reloaded. would that cause the code?

calico5string · 07-18-2009, 03:10 PM

Quote:

Originally Posted by lariat 7.3

so when i changed it from performance tune to tow tune it deleted then reloaded. would that cause the code?

I used an Edge "Evolution" programmer for a while. Whenever I would change programs, I would get a "KAM error" DTC also.

Again, when you change tunes, your messing with the PCM's program. The KAM ("Keep Alive Memory") is what keeps all of the drive-parameters stored and active when the truck is not running (your truck basically "learns" your driving style and remembers it). When you change programs, you have now changed some of the pre-set parameters in the PCM. Now they don't "jive" with what was stored from previous driving. This causes the PCM to generate an ERROR code (something changed in the PCM, without the PCM changing it).

Does that make sense?

Bottom line: don't worry about the code. Does your SuperChips programmer have the ability to read and clear DTC's? (The Edge Evolution does, that's one of the reasons I bought it) If so, just clear the code. It's not a problem. The KAM Error code will most likely return again the next time you change programs. No big deal, just one of the quirks of the computer...

BTW, that's one of the beautiful things about a chip rather than a programmer: instantaneous program changes...on-the-fly...with no codes, no errors. I much prefer the chip over the programmer (better tunes, too!)

PowerstrokeConverters · 07-18-2009, 04:36 PM

Second that, on the fly is waaaay better....the KAM code should be cleared when you go from perf to tow mode, a good programmer does that automatically, i know SCT and Superchips do, not that they are the best but are OK as handheld tuners go....I am having good results using the SCT on the highest setting now, never had the guts to do it because didn't have the gauges before, but my pyro results have been good so far.