Cadillac Repair: 1991 Cadillac Eldorado, cadillac eldorado, operator manual

Question
Service engine soon warning light activated.  How can I access the onboard computer to give me the information and service code to correct the default.  I have checked all fuses, fluid levels, connections, etc. and only found the transmission dipstick not seated fully down and an air hose connected to the rear of the air intake cover behind the carburator intake a little loose and secured it with a clamp.  The owners operator manual does not give directions on using the computer to access the service codes however I did find out how to access the codes from one of your current answers.  The current code is E048 with history codes of B120, B121, B122, R033 then it displays ECM?.  How do I clear these codes and the warning light and see if it comes on again. Thanks Tom

Answer
E048 = EGR control problem.

To CLEAR the E048 code:

1. Ignition ON, Engine OFF.

2. Simultaneously push and release the OFF and WARMER buttons for 3 seconds and release them.

3. after all the codes display and you see ECM?

4. Press and release the HI button and you will see ECM DATA?

5. Keep pushing and releasing the LO button until you see ECM CLEAR CODES?

6. Push and release the HI button and you will see ECM CODES CLEAR.

7. Press and release the OFF button until you see ECM?

8. Push and release the LO button and you will see BCM?

9. Press and release the HI button and you will see BCM DATA?

10. Keep pushing and releasing the LO button until you see BCM CLEAR CODES?

11. Push and release the HI button and you will see BCM CODES CLEAR.

12. Press and release the OFF button until you see ECM?

13. Press and release the LO button until you see SIR?

14. Press and release the HI button until you see SIR DATA?

15. Keep pushing and releasing the LO button until you see SIR CLEAR CODES?

16. Push and release the HI button and you will see SIR CODES CLEAR.

17. Press and release the OFF button until you see ECM?

18. Push and release the RESET button and turn OFF the ignition.

19. wait 2 minutes and start the car and see if the service engine soon comes back ON and if it does see what codes re-appear.