How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Ivan Your Own Question
Ivan, ASE Certified Master Technican
Category: Cadillac
Satisfied Customers: 4871
Experience:  ASE Master Tech w/ 20+ years in the field. Self employed for 9 years. Member of AUTOLAB radio show.
Type Your Cadillac Question Here...
Ivan is online now
A new question is answered every 9 seconds

1996 Cadillac DeVille: interior..doors..visor mirror lights..fuses

Customer Question

I have a 1996 Cadillac DeVille with Northstar, this car was stored for the winter and when i got it out the battery would not hold a charge, i replaced the battery with a brand new one since. My problem is none of my interior lighting is coming on, not when the doors are open as they should, as well as trying to turn on map lights manually, this includes all door lights, floor lights, map lights, and visor mirror lights, as well as my cigarette lighter is not working also. I have checked and replaced the fuses already to no success. Thank you
Submitted: 7 years ago.
Category: Cadillac
Expert:  Ivan replied 7 years ago.

Hello and thank you for using JustAnswer. I would like to start by asking you, do you have an analog instrument cluster or a digital cluster? I would like to send you a procedure to access any code store in the memory of the Body control module, hoping there will be a clue waiting for us. Let me know and I'll send you the procedure.


Your JA Expert,


Customer: replied 7 years ago.
I have a digital dash
Expert:  Ivan replied 7 years ago.

Go through this procedure and let me know all the codes that show up.





  1. Turn the ignition switch "ON."
  2. Push the "OFF" and "WARM" buttons on the Climate Control Center (CCC) simultaneously and hold until the segment check appears on the Instrument Panel Cluster (IPC) . NOTICE: Operating the vehicle in diagnostics for extended time periods without the engine running or without a battery charger will cause the battery to run down and possibly relate false diagnostic information, or cause a "no start" condition. To ensure proper operation, attach a battery charger if vehicle is to be operated in diagnostics without engine running for an extended time period.

The purpose of illuminating the IPC is to verify all segments of the LED displays are working. The turn signal indicators do not light during this check. Further diagnosis should not be attempted unless all segments appear, as this could lead to misdiagnosis. If any portions or segments of the IPC displays are inoperative, the IPC must be replaced.

After diagnostics are entered, any DTCs stored in computer memory will be displayed. Each DTC consists of the system abbreviation (P - PCM, IP - IPC, AC - ACM, SD - SIR, TCS -TCS, RS - RSS, PZ - PZM, IR - IRC, RF- RFA, CC - CCP or PH -PHN), a four digit identifier, and the letter C or H. All DTCs for each system are displayed together, in consecutive order by their four digit number (lowest first - i.e. PZ 2016, PZ 2096, etc.). The final digit of the code, a "C" or an "H", is used to indicate whether the DTC is current or history. A "C" means the malfunction was still present the last time the diagnostic test was run, while "H" means the failure was not present the last time the DTC was tested for. If no DTCs are present for a system, a "NO X CODES" message (with X being the system i.e. PCM, IPC, ACM, SIR, TCS, RSS, PZM, IRC, RFA, CCP or PHN) will be displayed. If the communication line to a component is not operating, a "NO X DATA" message will be displayed, indicating that the IPC could not communicate with that system. At any time during the display of DTCs, if the "MODE" button on the IPC is pressed the system will exit "Service Mode" and go back to normal vehicle operation.

After trouble codes have been displayed, a specific vehicle system PCM, IPC, ACP, SIR, TCS, RSS may be selected for testing.

The first available system will be automatically displayed (i.e. PCM?). While selecting the system to test, any of the following actions may be taken:

  1. Depressing the "HI" button will select the displayed system for testing.
  2. Depressing the "LO" button will display the next available system selection. This allows the display to be stepped through all system choices. This list of systems can be repeated following the end of the system list.
  3. Depressing the "OFF" button will stop the system selection process and return the display to the beginning of the trouble code sequence.
  4. Pressing the "OFF" button twice will return the system to the segment check.

Having selected a system, the first available test type will be displayed (i.e. PCM DATA?, PCM CLEAR CODES?). While selecting a specific test type, any of the following actions may be taken:

  1. Depressing the "HI" button will select the displayed test type. At this point the first of several specific tests will appear.
  2. Depressing the "LO" button will display the next available test type for the selected system. This allows the display to be stepped through all available test type choices. This list of test types can be repeated following the display of the last test type.
  3. Depressing the "OFF" button will stop the test type selection process and return the display to the next available system selection.

Selection of "CLEAR CODES?" test will result in the message "CODES CLEARED" being displayed along with the selected systems name. This message will appear for 3 seconds and then return to the next available test type.

To get out of the diagnostic mode anytime during the test, depress the "MODE" or "DEFOG" button, or turn the ignition switch "OFF." Trouble codes are not erased if this is done prior to selecting "CODES CLEARED."

Customer: replied 7 years ago.
Thank you again for your time. Here is a list of all codes current or history that I recieved during the diagnostics.
PC0603 History
PC1520 Current
PC1810 Current

IP1552 History
IP1911 History

PZ1558 History
PZ1971 History
PZ2471 Current

I would also be curious to know the stored "History" codes meaning if you could direct me to them. Also I've noticed today that this has also affected my trunk and gas door release buttons as they are inoperable as well.
Expert:  Ivan replied 7 years ago.

I'll find you everything. I have to run out for a few hours and will look everything up for you as soon as I get home. Thanks for recovering the info.



Customer: replied 7 years ago.
Not a problem, Thank You again
Expert:  Ivan replied 7 years ago.

PC0603=PCM reset

PC1520=Gear indicator problem

PC1810=Automatic Transmission Fluid Pressure Manual Valve Position Switch


IP1522=I couldn't find a definition

IP1911=Alternator L-terminal fault malfunction


PZ1558=EEPROM Checksum error

PZ1971=Inadvertent power fault

PZ2471=Interior Lamp fault


With that all said, now I'd like you to go through the procedure to clear all the codes, cycle the key off, wait a few seconds, then exit the vehicle and reenter and see if there is any change.

Customer: replied 7 years ago.
I have cleared all the codes as you suggested. upon re-entering the vehicle i immediatly noticed the passenger door was illuminated (small light above door handle) I then started the vehicle and upon further inspection was able to verify all door handle lights working as well as the cigarette ashtray lights. These were previously outed. However I still have no map lights, rear "dome" lights, floor lights, glovebox lights, as well as my trunk and gas door releases are still not working. As i believe i stated previously my entire dash cluster, and all dash backlighting (i.e Stereo, climate controls, headlight controls) are functioning properly. I sincerly appreciate your efforts thus far and any other suggestions you may have.
Thank You
Expert:  Ivan replied 7 years ago.

Patrick, at least we are making progress. All these items are controlled by the BCM, so let's cover some bases. Go to the fuse box in the trunk and make sure we have power to both sides of the fuse labeled CONVENC. It's a 20 amp fuse for the fuel door. Also in the engine compartment fuse box, check the fuse labeled: INT LIGHTS. It's a 10 amp and that's for the glove box light along with the trunk light, map lights and floor and rear lights. There are other control aspects to some of these items, but let's start by confirming 12 volts on these fuses. Let me know, also recheck the codes to see if anything came back.



Ivan and 2 other Cadillac Specialists are ready to help you
Customer: replied 7 years ago.
I appologize sincerly for the amount of time between responses. I have since discovered the alternator has been defective this entire time as my new battery was slowly drained after a few times driving the vehicle. it has been tested and found to be defaulted. I have submitted the vehicle to a certified mechanic at this point. I very much appreciate your time on this matter. Thank You
Expert:  Ivan replied 7 years ago.

You are very welcome. If you need anything, don't hesitate to ask. I'll be here for you if you need me.