Cadillac Audio, Video and Security Systems Discussion, 98 Deville OEM HU Re-install Question in Item Specific Cadillac Discussion; My car is a 98 Deville. I removed the OEM HU AM/AF/Cassette made by Delco. I installed a 98 Deville ...
My car is a 98 Deville. I removed the OEM HU AM/AF/Cassette made by Delco. I installed a 98 Deville OEM AM/FM/Cassette/CD (Delco), had it unlocked by the dealer. No Sound. If I re-install the original AM/FM/Cassette, will it have to be unlocked by the dealer again? Each visit is $47.50. I am going to install a 12 disk remote in the trunk (oem). All I wanted to to have CD.
NO, the original HU once is locked for your car will work in that car even if is removed for 20 years.
Here is how it works:
The HU has a small permanent memory reserved for the VIN of the car is installed in. When the firmware is installed in the HU from factory, this memory is empty. In the starting sequence the firmware reads the VIN from the PCM (or DIM for the '98+ Sevilles and '00+ Devilles). If after reading the VIN from the car network the HU VIN memory is empty, the VIN will be permanently stored in this memory and HU will continue with the starting sequence. If the HU VIN memory is not empty then the firmware compares the VIN form PCM (or DIM) with the one in the HU memory. If the two numbers match then it will continue with the starting sequence, if not then it will post a message ("THEFT LOCK ENABLED" for BOSE units or "LOCK" for base units) and issue a code on the car data bus. The IPC will receive this error code and may post the message "Theftlock enabled car may not restart".
When you go to the dealer (actually you went to unlock the other HU) they connect with the TechII tool to the car data bus (thus to the HU) and send a special command to the HU to erase the VIN from his memory. At this moment the HU will restart and since his VIN memory is empty will read and store the VIN from the car is currently installed in.
Hope I was clear enough, is not very complicated concept.
Any how as a conclusion at this moment you own 2 HU with your car's VIN in memory. So you can use at any moment time any of them, just that the BOSE unit can not be used (sound wise) unless you convert the whole car to BOSE.