Cd player in 2001 GMC Sierra displays ERR but everything else works.?
- Thread starter Brian
- Start date
Molson02536
New member
There are 2 types of GM Theftlock, Theftlock I and Theftlock II. The Theftlock I is found in pre 2000 vehicles, and Theftlock II is in the later models.
Theftlock I - Uses a volatile user settable code that is input through the key pad on the front of the Radio. If the power is lost (dead battery etc.) the code is gone and must be re-entered for the radio to work. But with the correct procedure the owner can unlock it.
Theftlock II - Uses an EPROM (erasable/programmable read only memory) or a PROM (the difference is you can not alter the prom once it is programmed).
In either case the code is burned in and holds even when the power is lost. With Theftlock II the radio is married to the vehicle by way of the VIN. When the vehicle is started the computer compares the number in the radio with the VIN in the body control module. If they match, the radio works, if not the radio displays LOC and you are finished, there is no easy way around it. The radio will not work until you make a trip to the dealer.
The dealer will use a TECH 2 scanner to change the VIN stored in the radio. The radio does not need to be removed (for the serial number or any other nonsense). The technician just plugs into the computer and resets the VIN in the radio.
With that said, most of the time your CD just needs to be reset with the TECH2 scanner. AT the same time it will test the Radio for you and let you know if it's mechanical or software issues. But here is the big secret, Pull the fuse to your Radio for 2 min and this should reset you radio back to default. your going to have to reprogram the time and reset station, but things should be back to normal if there is no mechanical failure to your radio's CD.
Good luck and keep us posted.