View Full Version : need trouble code definitions

05-29-04, 06:11 PM
I have several problems with my 1999 Devile and got my trouble codes by pressing the off and warmer buttons on my counsel. The codes that were identified are PCM P0404, P0603 and P1599 also IRC B 1771 and TCS C1225. Does anyone have a list of definitions for these codes and the corresponding actions to take to correct these problems.

05-29-04, 08:07 PM

05-29-04, 09:06 PM
Hi 1999caddy -

Here's a little info to get you started:

P0404: Exhaust Gas Recirculation (EGR) Open Position Performance
This may be a failed or failing EGR valve or sometimes they can get very crusted up with carbon and a cleaning will get it back in shape.

P0603: Control Module Long Term Memory Reset
This could be a failing or failed PCM (computer). If it's a HISTORY code, make a note of it and clear it out. If it comes back or shows CURRENT, the PCM may need to be replaced.

P1599: Engine Stall or Near Stall Detected
Hmm. Pretty much self-explanatory there. Doesn't say what the cause of the problem is, but you probably knew that anyway. May be the result of the previous two codes.

B1771: Cassette Tape Slow
Get a faster cassette tape, perhaps an urban dance mix. :D Perhaps the cassette drive mechanism or motor is failing or a tape got jammed in there. I'm not absolutely sure about the translation for this code, though.

C1225: Left Front Excessive Wheel Speed Variation
That sounds to me like a failing wheel speed sensor, which is part of the wheel bearing. Check the wiring for the sensor or replace the wheel bearing.

Your best bet may be to buy the service manual from Helm. You can order the 3000+ page shop manual for your 1999 Deville at the following link:


There's quite a variety of problems indicated there. The P0603 is the most troubling, in my opinion. A dealership might have to do that one. Hope that gets you what you need. I'm sure others will chime in with other suggestions, corrections, and opinions. I may be completely wrong. Either way, let us know how it goes. Good luck!

05-31-04, 01:07 PM
I believe that other posts on the subject of the P0603 have said that this code can be triggered by something as simple as disconnecting and re-connecting the battery as you would when changing to a new battery.