Hey guys,
I know this an old thread, but, I thought I'd let you all know of my findings in this case. I decided to do this myself in order to have my radio control my factory compatible CD changer instead of using an FM modulator. First of all, you can actually make a newer Delco/Delphi head unit work without class 2 data buss and/or without programming by unlocking, or, technically "jailbreaking" the unit. All newer Delco/Delphi newer head units with a "Band" button and/or the multi-disc symbol are both CD changer and/or XM radio compatible which can give you a few more options. They are also all pretty backwards compatible with a few exceptions.
How to make the head unit work is rather simple. As described in the previous post, You can de-solder pin 8 on the security chip marked 9355093, however, I have dug deeper than that and thought I'd share with all of you my findings. First of all, I recommend simply removing the chip completely. After you de-solder pin 8, the head unit becomes automatically compatible with every GM class 2 vehicle out there, and, in some casses, even E&C and non data bus vehicles, and, there is basically no point to leaving the chip in otherwise. This chip is also what causes a GM tech 2 scan tool to free and restrict certain features of the radio as well such as XM and others. If you're wanting a head unit that is going to be compatible with all vehicles, and, will power o via 12 volt ignition, you want a Delco/Delphi unit made prior to 2004 with a date code sticker on the top panel, and, no Delphi part number on the side sticker. Inside the head unit, you will find the security chip located close to a front corner of the main board. For example; On a Chevrolet head unit, the chip should be located on the underside of the board toward the front inside opposite the audio adjustment knob. On a Pontiac head units, you'll find it in the same corner toward the front opposite the Traf, Prog/Type, and HR/MN buttons. Before removing the chip, remove the faceplate, front metal panel, and, if applicable, the cassette drive for easy access to the chip.
Class 2 head units made from 2004 to around 2006 and some newer, have the date code and a Delphi part number on the side panel. These units are designed to power on by data bus only and will not power on by 12 volt ignition power. These units also have the chip directly in the middle underside of the main board.
For either type, I recommend removing the chip instead of taking it to a dealer for programming where as in some cases, programming may cause features to be restricted such as a CD changer or XM radio tuner.
Precautionary note: On vehicles older than 1995 with an early E&C data buss, I do not recommend connecting it to the unit due to it will prevent the unit from accessing any external add-ons or devices, however, will help it to retain it's preset and audio settings if it is connected. On vehicles made 1995 or newer with E&C 1.5 and/or Class 2, connecting the unit to the data buss
should not cause any issues. Also, remember, in this case, "Calibrate" and/or "Cal Error" is a good thing.
Some head units may have a memory loss issue with presets, last function used, and EQ position when they are not connected to a data buss.
Remember, all newer units have a delayed power off sequence even when RAP is not involved. This is residual power leaving the capacitors of the unit, and, if you have an amp connected, it is normal to hear a bass pop from the speakers a few seconds after you have turned off the unit or vehicle.
The part numbers of at least the MP3 head units compatible with all vehicles with or without Class 2 data bus are:
10348717 (Chevrolet Head Unit)
10348716 (Pontiac Head Unit)
15216905 Series 1 (Chevrolet/GMC Truck head unit)
Compatible with vehicles with E&C 1.5 or class 2 only:
15216905 Series 2 (Chevrolet/GMC Truck head unit)
28016697 (Pontiac Head Unit)
Please take note that this can apply to almost all Delco/Delphi class 2 head units. Just to let you all know, I have the Pontiac unit in my vehicle, however, it has the memory issues.
I hope this helps.
Starflare5.