Delco AM/FM/CD "LOC" Message

mcmlxv · March 15, 2005

I own a 2004 Silverado 2500HD Work Truck. I replaced the stock AM/FM radio, code UM7, with the AM/FM/CD radio, code U1C. U1C is the same in appearance to the UM7, but with a CD slot an two extra control buttons on the face. It's the entry-level optional, non-RDS CD player that was offered on the Cavalier, Classic, and current Express van. I really like this radio because it's easy to operate and doesn't include all the electronic junk (RDS, AutoTone, AutoVol, and Traffic) that doesn't work and I don't need.

When I installed the radio, I expected to receive a "LOC" error on the display, and I did. I checked with some online vendors who claim to be able to supply the unlock codes for Delco radios. I was instructed to retrieve the 6-digit code by pressing buttons 2 & 3, writing down the first 3-digit sequence, then press AM/FM to retrieve the second 3-digit sequence, and then mailing them the 6-digit sequence to have the final code returned to me. I was not able to retrieve any digits, so I took the truck to the dealer.

My local GM dealer spent almost an hour trying to unlock the radio. Again, no success. The GM tech (Thank you Dan & Steve at Quirk Chevy in Braintree MA. Courteous & no charge!) explained to me that because the U1C radio was not available on the Silverado, the computer doesn't contain the necessary software to recognize this radio, and never will interface with said radio, ever. Is the Tech correct?

Is there any way to unlock this radio?

Help...

Thank you in advance!

GM-Tech · March 15, 2005

explained to me that because the U1C radio was not available on the Silverado, the computer doesn't contain the necessary software to recognize this radio, and never will interface with said radio, ever. Is the Tech correct?

Yeah, I'd say they're right. As you found out, radios are no longer locked by a customer input code, but by the radio learning the VIN of the vehicle.

Radios have to be programmed when replaced. We can only program based on what possible options are available for that vehicle. They *might* be able to get a VCI number from Techline that will allow programming, but I doubt it.

We've put in radios that were identical in appearance and function, but had a different part #. We were not successful in programming those radios.

mcmlxv · March 15, 2005

Thank you for your quick response! Looks like I'm stuck...

BBSilverado · March 16, 2005

I own a 2004 Silverado 2500HD Work Truck. I replaced the stock AM/FM radio, code UM7, with the AM/FM/CD radio, code U1C. U1C is the same in appearance to the UM7, but with a CD slot an two extra control buttons on the face. It's the entry-level optional, non-RDS CD player that was offered on the Cavalier, Classic, and current Express van. I really like this radio because it's easy to operate and doesn't include all the electronic junk (RDS, AutoTone, AutoVol, and Traffic) that doesn't work and I don't need.

When I installed the radio, I expected to receive a "LOC" error on the display, and I did. I checked with some online vendors who claim to be able to supply the unlock codes for Delco radios. I was instructed to retrieve the 6-digit code by pressing buttons 2 & 3, writing down the first 3-digit sequence, then press AM/FM to retrieve the second 3-digit sequence, and then mailing them the 6-digit sequence to have the final code returned to me. I was not able to retrieve any digits, so I took the truck to the dealer.

My local GM dealer spent almost an hour trying to unlock the radio. Again, no success. The GM tech (Thank you Dan & Steve at Quirk Chevy in Braintree MA. Courteous & no charge!) explained to me that because the U1C radio was not available on the Silverado, the computer doesn't contain the necessary software to recognize this radio, and never will interface with said radio, ever. Is the Tech correct?

Is there any way to unlock this radio?

Help...

Thank you in advance!

<{POST_SNAPBACK}>

The U1C radio is not compatibale with the silverado or any full size truck/SUV. You must get one made for the GMT800 platform vehicles and it will have to be unlocked if it was a used one (a brand new one will not be locked and when I say brand new I mean never even installed in a vehicle.) The closest match to what you want is a UB0 radio part no. 15198700.