Application Information: Chevrolet: F, Y, Cars, U Van Pontiac: A, F, H, W Cars Oldsmobile: B, H, N, W Cars Buick: A, B, C Cars
The following information updates all existing Service Manual information.
The procedures below explain how to operate the Delco LOC II security system. This includes entering and removing customer codes, unlocking the radio, obtaining the factory display code, and obtaining the factory backup code.
Different model radios use different buttons to set the codes into the radio. To determine which two buttons to use, determine if the radio has a seek button, a seek up/down button, or no seek button at all.
If the radio has a seek button, use seek and scan to set the codes as described below.
If the radio has a seek up/down button, use seek up/down and tune up/down to set the codes and substitute these buttons for seek and scan in the procedures below.
If the radio has no seek button, use tune down and tune up to set the codes and substitute these buttons for seek and scan in the procedures below.
Different model radios have different functions attached to the radio presets. Below is the present configuration of dual functions depending on the radio have a seek button, seek up/down or no seek button at all.
SEEK BUTTON: Presets 1 (PREV), 2 (NEXT), 3 (REV), 4 (FF), 5 (COMP)
SEEK UP/DOWN: Presets 1 (PREV), 2 (NEXT), 3 (REV), 4 (FF), 5 (COMP)
NO SEEK: Presets 1 (REV), 2 (FF), 3 (COMP), 4 (REPT), 5 (SRCH) 6 (SCAN)
"LOC" Means the radio is locked and there is a customer code stored in the radio.
"InOP" Means too may wrong codes have been entered and the radio must be left powered up for 1 hour with battery and ignition applied before 3 more attempts can be made.
"SEC" Means there is a customer code stored but the radio is unlocked.
"---" Means there is a customer code stored and the radio is unlocked.
"REP" Means you have entered your customer code once, and the radio now wants the code repeated again to verify you entered the correct code the first time.
---------- A. TO UNLOCK RADIO - From 'LOC' display Mode on Power Up After Battery Power is Removed
RADIO DISPLAY ------- Display comes up "LOC" LOC 1. Press the set button 000
2. Set the first digit (0-9) of your code with the seek button. 100
3. Set the next two digits (0-99) of your code with the scan button. 123
4. Press the am-fm button to enter the first three digits. 000
5. Again, use seek to set the 4th digit (0-9) 400 of your code.
6. Set the last two digits (0-99) of your code with the scan button. 456
7. Press the am-fm button to enter the last 3 digits of your code.
Radio is unlocked and clock is displayed. 1:00
B. TO REMOVE CUSTOMER'S CODE-Deactivate Theft Deterrent From Unlocked Mode, Deterrent Activated.
1. With the radio off, hold in presets 1 and 4 for about 4 seconds until the display changes to SEC.
2. Press the set button 000
3. Set the first digit (0-9) of your code with the seek button. 100
4. Set the next two digits (0-99) of your code with the scan button. 123
5. Press the am-fm button to enter the first three digits. 000
6. Again, use seek to set the 4th digit (0-9) of your code. 400
7. Set the last two digits (0-99) of your code with the scan button. 456
8. Press the am-fm button to enter the last 3 digits of your code. 1:00
Theft deterrent is deactivated and '---' then clock '---' is displayed '1:00'
C. TO ADD CUSTOMER'S CODE-Set User Code (activate) From Unlocked Mode, Deterrent Deactivated.
1. With the radio off, hold in presets 1 and 4 for about 4 seconds until the display changes to '---'.
2. Press the set button '000'
3. Set the first digit (0-9) of your code with the seek button. '100'
4. Set the next two digits (0-99) of your code with the scan button. '123'
5. Press the am-fm button to enter the first three digits. '000'
6. Again, use seek to set the 4th digit (0-9) of your code. '400'
7. Set the last two digits (0-99) of your code with the scan button. '456'
8. Press the am-fm button to enter the last 3 digits of your code. 'REP'
9. When 'REP' the '000' are displayed, repeat steps 3 '000' through 8 of this procedure to enter your code again before the display changes back to clock. This confirms your customer code, activates the theft deterrent, and after step 8 displays the 'SEC' to show the theft deterrent has 'SEC' been activated. Any time battery power is cycled and ignition is applied the display will show 'LOC' and need to be unlocked 'LOC' by either your customer code 'LOC' or the factory backup code.
D. To display Radio Display Code (Scrambled Backup Code)
1. Press and hold presets 2 and 3 for about 8 seconds until the first 3 digits of the display code are displayed. '123'
2. Please write the number down. '123'
3. Press the am-fm button. The second 3 digits of the display code are displayed. '456'
4. Please write the numbers down. '456'
This display code can be unscrambled to get the factory backup code to unlock the radio by calling the Delco Phone number and entering the display code along with you authorization code.
E. To obtain Factory Backup code After Obtaining Display Code (Step D)
1. After obtaining the display code in Step D call 1-800-537-5140 (U.S. and Canada) or (317) 451-8965. (You will need your six digit dealer code number).
2. When the computer prompts, using a Touchtone (TM) telephone, enter your 6 digit dealer code, then press *. For example, if your dealer code is 213063, then you would enter 213063*.
3. When prompted, enter the 6 digit radio display code, then press *. The computer will respond with the factory backup code. Please write it down. The computer may give you two possible codes. If the first code does not unlock the radio per step A, then use the second code. On some models another possible backup code is O's. Refer to step A to use these factory backup codes.
F. To Change Customer's Code
Once the radio is unlocked and the old customer code is removed by following parts A and B, enter the new customer code by following Step C.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.