2002 Deville computer issue?

2002 Deville Base

  1. Battery went dead due to light being on
  2. Removed battery and charged. reinstalled. Shows proper voltage
  3. Car started up and runs fine.
  4. No radio. Getting power. Fuses ok. No station display or sound.
  5. Security, traction, air bag, and battery light on dash all stay on.
  6. Get coolant warning , oil change warning, ect. Checked and no problems with levels etc.
  7. Key fob stopped working. Changed battery. still not working.
  8. Everything else seems to work.

Next day battery was dead again. Checked for parasite draw and pulling fuse for radio. Recharged battery and it stayed charged and started right up.

Only current code is IPC U1000 which I assume is due to radio not working.

Any help in getting radio working, lights off, and fob working?

Car “computers” rarely go bad.

Have you replaced your battery with a brand new one? You mention having to recharge it several times. Usually a discharged battery just needs to be replaced.

All of the odd symptoms you mention remind me of a bad, or dying battery. Modern car electrical systems are finicky about a steady supply of power.


When a battery dies or is disconnected on today’s vehicles, it can cause all sorts of problems.



Replaced battery with new one. No change

A 2002 car… with nearly 20 years to corrode ground wires. I’d be looking for poor ground connections. Battery ground wire, body grounds, under dash grounds, the works. Electrical problems on old cars very often are ground problems.

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If you know how to work a DVM, you could try this experiment.

Before first start of the day (i.e. car unused overnight) the battery should measure about 12.6 volts. Then immediately after starting the engine, 13.5-15.5 volts. What do you measure?

Check Tester’s link and also Mustangman’s ideas I thing the problem is going to be the radio being disconnected as they are a big part of the security and computer systems now a days.

You may have to take it to the dealer and get the computer reprogrammed. There are some vehicles that lose critical parts of their programming when all voltage, either from battery removal or dead battery, is lost.

EDIT: most likely the BCM (body control module) is the one that needs reprogramming.

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A failing alternator might be a possibility. I’d have it checked to rule it out, anyway. A lot of the parts stores offer free testing. Also, you can try removing the battery cables and turning the ignition key like you’re trying to start the car. This discharges any stored electrical energy and basically serves as a computer reset.

On a 2002 model? Highly unlikely. That degree of integration did not exist back then. By 2007, manufacturers started putting the car stereo on the computer bus, and by 2010, manufacturers started integrating the climate control and security system into the stereo. But in 2002, the stereo was just a stereo. It did not control or interface with anything else.

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GM did have the “Theftlock” passive security system back in 2002. Not sure how elaborate it is. I think it just keeps the car from starting at all.

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