Cadillac Repair: Service engine Light, negative battery cable, cadillac deville

Question
QUESTION: I have a 1993 Cadillac Deville and my service light went on.  I did the on board diagnostics and it gave me a code E85.  It seems to be running fine but I would like to fix it because I have a long family trip to go on.  Can you please help.

ANSWER: E85 means that the throttle plate has an accumulation of a blackish foreign debris in the throttle body bore and this residue is not allowing the throttle plate to close all the way.

Sometimes you may notice a slightly higher idle speed than you normally have.

This can be fixed by cleaning the throttle plate and sorrounding bore using carburator cleaner or similar spray bottle type compound that you can purchase at any auto supply store.

If you would like pictures and the procedure for cleaning theis area, E-mail: onlineautohelp@msn.com

---------- FOLLOW-UP ----------

QUESTION: I cleaned it really good with carburetor cleaner and a tooth brush and it is very clean.  I reset the light and restarted the car and the light came back on in about 5 seconds.  Is it possible that it could be a switch or sensor?

Thanks
Brian

Answer
OK, Lets try an IDLE SPEED RE-LEARN procedure.

1. Disconnect the negative battery cable for 10 seconds and then reconnect it.

2. Turn ignition ON and enter diagnostics via the climate control panel.

3. Turn ignition OFF and wait 20 seconds for the ISC motor to retract.

4. Turn the ignition ON.

5. Re-enter diagnostics via the climate control panel.

6. Turn the ignition switch OFF.

7. Start the engine.

8. Allow to idle for 13 minutes.

9. Place transmission in drive with brakes applied.

10. Place the climate control panel in the OFF position for atleast 1
   minute.

11. Make sure the outside air temp is above 50 degrees.

12. Place the climate control panel in the AUTO position for at least
   1 minute.

13. Place transmission in PARK and turn OFF ignition.

14. Wait 5 minutes and restart the car and see what the idle speed does.


15. If the idle is still high, we need to check the TPS and ISC adjustments.

Have you made any adjustments to anything and or replaced any parts to try and resolve this problem other than what I told you earlier ?.