This is an update to my post on:
http://www.automotiveforums.com/vbul...d.php?t=472260
Yes, I was able to bypass theftlock in the mp3 CD Head unit
Sorry for the disorganized text, it is close to 2am but I have received a few questions about the outcome and wanted to post for all.
I have an 01 Impala with the Class II CD/RDS radio and it turned out the 15216905 mp3 radio I bought was from a S10
(these vehicles belong to different body platform and have different body control modules, the dealer wasn't able to reprogram the vin with a TechII... this didn't work under neither vehicle's platform/body choices in the techII)
Anyway long story short, I was looking at the circuit boards of both radios and found a small 8 pin chip that was a 4Kb EEProm .
I figured this could be where the vin is stored and maybe other vehicle settings that can be changed by through the radio.
I tried to exchange these EEProms between both radios with the rationale that I would bring the vin and settings from one to the other but this did not work.
It results in a 'CAL ERROR' message for ~1-2 secs when the radio is on.
An interest side effect is that Theftlock was completely bypassed
So I returned each EEPROM to the radio they belonged to
but left pin 8 of the EEPROM not soldered/connected. (pin eight is power to the EEPROM)
Except for the CAL ERROR message for a 1-2 secs when I turn on the radio, all works perfect.
All sound settings, bass, treble, radio stations, resume place on the cd/mp3 are stored when the vehicle is shutdown too.
All integration/Class II features:
Chimes, OnStar, dimming, off when door open etc work fine too
Bottom line, just find the 9355093 8 pin serial EEPROM, take a soldering iron and a very small screwdriver/knife.
Heat pin #8 and lift/pry *very* carefully so it no longer contacts board.
that's it.
http://www.tranzistoare.ro/datasheets/134/80474_DS.pdf
Here is a datasheet to the chip if you need help figuring out which is pin 8
(9355093 = 24c08 EEPROM)
On the MP3 Head Unit circuit board there are two small 8 pin EEPROMS near the pushbutton/tone button area.
One that says AMI, the other says 9355093
The one you want is 9355093 .
BTW, with a new HU I obviously lost the Impala specific 'hold display' button to customize the impala body module settings.
Nevertheless it still retains the settings I last programmed with the previous HU. (which can be plugged again in a pinch if needed to alter any of these settings)
On the new HU, if you hold '6' for a while you can THANKFULLY switch the chimes to a lower volume.
Disclaimer: I have not tested this in any other scenario other than the above
(15216905 MP# HU from a Chevy S10). YMMV but in my opinion, provided you have some soldering skills and follow ESD precautions, the risk of lifting the power pin on the EEPROM is low and can be reversed easily if any issues.