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GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15181
Experience:  GM Grand Master Technician 2007. 14 years experience.
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Need a code to unlock anti-thief radio chevy cheyenne

Customer Question

need a code to unlock anti-thief radio for 99 chevy cheyenne
Submitted: 9 months ago.
Category: Chevy
Expert:  Ryan Schott replied 9 months ago.

turn the ignition on radio off press and hold the preset 2&3 buttons then write down the first three digits that appear then press AM/FM write down the second three digits. then send me the whole vin and this six digit code

Customer: replied 9 months ago.
VIN: 1GCEC34R0XZ184045
the radio only showed 4 numbers : 2700
Expert:  Ryan Schott replied 9 months ago.

the first time when you pressed 2 and 3 it displayed that? did it not change upon pressing am/fm

Customer: replied 9 months ago.
displayed nothing, pressed 1 & 2
Expert:  Ryan Schott replied 9 months ago.

ok give me a few minutes

Expert:  Ryan Schott replied 9 months ago.

7925

Expert:  Ryan Schott replied 9 months ago.

and heres the process to use it

C. Unlocking/ deactivating unit with back-up code or customer code - with battery and ignition voltages applied and radio power off.

  1. Press the HR button until the LOC disappears and OOO appears on the display.

    Note: If the display does not change from LOC to 000 the unit is probably in the InOP stage, see Step G.

  2. Set the first two digits (01-19) of the code with HR (hours) button
  3. Note: As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.)
  4. Set the next two digits (00-99) of the code with the MIN (minute) button.
  5. Press the AM-FM button to enter the code. The radio will now be unlocked and the display will change to the clock. Continue with the following steps to deactivate the theft deterrent.
  6. Press the HR button until display changes 000.
  7. Repeat steps 2-4 above to remove previous code and deactivation the theft deterrent system.

Note: If the backup code received from the computer does not unlock the radio, one possibility is that the first 3 digits of the scrambled code from the radio (Step A) are reversed with second 3 digits. Example; if the scrambled code is 123 456, then it may actually be 456 123. Use Step B retrieve a new backup code.

D. Removing customer code - with battery and ignition voltages applied and radio off.

  1. Depress presets 1 and 4 for about 6 seconds until the display changes to "SEC". If the display changes to --- there is no code stored.
  2. Press the HR button until display changes to 000
  3. Set the first two digits (01-19) of the code with HR button.

    Note: As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.)

  4. As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.).
  5. Press the AM-FM button to enter the code. The theft deterrent system will now be deactivated and customer code removed. The display will show --- and then change the clock.
Customer: replied 9 months ago.
it doesn't accept the code
Expert:  Ryan Schott replied 9 months ago.

here i will send you this whole PI follow the instructions carefully and send me the code it gives you again

Subject:Procedures to Unlock Family Radio with Theftlock

Models:1994 - 2002 GM vehicles that have a Delco TheftLock radio

This PI was superseded to update Recommendation/Instructions. Please discard PIC4696A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

This procedure will correct all radio theftlock concerns for the vehicles listed. Please read the following carefully! There are time limits associated with some of these steps. Therefore, if the directions are not followed properly, unnecessary wait time will occur. The mode the radio theft deterrent system is in will determine which steps to be followed.

Recommendation/Instructions

The TheftLock logo will appear on the face plate of the radio to indicate this radio has the protection of TheftLock. The Pontiac, Buick, Chevrolet and light trucks will have an indicator light that blinks when the vehicle is off and this feature is activated. Oldsmobile radios do not have the light indicator. The feature is activated by the customer programming a code into the radio. Instructions are in the customer's owner’s manual. The procedures in this section explains how to operate the theft lock security system. This includes unlocking the radio, removing and entering customer's code, obtaining the radio display code, and changing the customer's code.

The theftlock theft deterrent feature in some models includes an LED indicator light that will blink when the ignition is off and the unit is in the secured state.

Radio display definition:

LOC: Means the radio is locked and there is a customer code stored in the radio.

InOP: Means too many wrong codes have been entered and the radio must be left powered up to 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 no customer code stored and the radio is unlocked

REP: Means the customer code has been entered once, and the radio now wants the code repeated to verify the code was entered correctly the first time.

Index of procedures:

A. Retrieving scrambled back-up code from unit

B. Retrieving back-up code from computer (authorized dealers only)

C. Unlocking/Deactivating unit with back-up code or customer code

D. Removing customer code

E. Adding customer code

F. Changing customer code

G. InOP second level condition

A. Retrieving scrambled back-up code from unit - with battery and ignition voltages applied and unit power is on.

  1. If the unit is in the locked condition (LOC is displayed), proceed to step 2. Otherwise, press and hold presets 1 and 4 for about 4 seconds. The display will show either SEC or ---.
  2. Press and hold presets 2 and 3 for about 6 seconds until the first 3 digits of the display code are displayed. Write the numbers down.
  3. Press the AM_FM button and the second 3 digits of scrambled code are displayed. Write the numbers down. The unit will revert to the initial display, prior to code retrieval sequence, after approximately 5 seconds or if another button is pressed.

Note: Press the AM_FM button and the second 3 digits of scrambled code are displayed. Write the numbers down. The unit will revert to the initial display, prior to code retrieval sequence, after approximately 5 seconds or if another button is pressed.

B. Retrieving back-up code from computer (GM and ACDelco dealers) - scrambled code and authorized lock account number must first be obtained.

  1. GM dealerships- your authorized lock account number is ***** up by the corresponding digit for your controlling car division preceding your 5-digit GM- dealer code. For example, if your GM-dealer code is 01234, and your controlling car division is Chevrolet, then your authorized lock account number would be 101234.

    1- Chevrolet/Geo 5- GMC

    2- Pontiac 6-Cadillac

    3-Oldsmobile7- Canada

    4-Buick8 -Saturn 1991-1999 with Delco radios

    AC-DELCO Shops- Your authorized lock account number is ***** up by a 9 & 0 followed by your 6 digit AC-Delco account number. For example, if your AC-Delco account number were 123456, then your authorized lock account number would be###-##-####

  2. Dial(###) ###-####and listen to the phone prompts. Enter your authorized lock account number followed by an asterisk (*). The next prompt will be your scrambled code that was obtained from step A, followed by an asterisk (*). The computer will respond back with 4 or 6 digit back- up code.

C. Unlocking/ deactivating unit with back-up code or customer code - with battery and ignition voltages applied and radio power off.

  1. Press the HR button until the LOC disappears and OOO appears on the display.

    Note: If the display does not change from LOC to 000 the unit is probably in the InOP stage, see Step G.

  2. Set the first two digits (01-19) of the code with HR (hours) button
  3. Note: As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.)
  4. Set the next two digits (00-99) of the code with the MIN (minute) button.
  5. Press the AM-FM button to enter the code. The radio will now be unlocked and the display will change to the clock. Continue with the following steps to deactivate the theft deterrent.
  6. Press the HR button until display changes 000.
  7. Repeat steps 2-4 above to remove previous code and deactivation the theft deterrent system.

Note: If the backup code received from the computer does not unlock the radio, one possibility is that the first 3 digits of the scrambled code from the radio (Step A) are reversed with second 3 digits. Example; if the scrambled code is 123 456, then it may actually be 456 123. Use Step B retrieve a new backup code.

D. Removing customer code - with battery and ignition voltages applied and radio off.

  1. Depress presets 1 and 4 for about 6 seconds until the display changes to "SEC". If the display changes to --- there is no code stored.
  2. Press the HR button until display changes to 000
  3. Set the first two digits (01-19) of the code with HR button.

    Note: As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.)

  4. As if you're setting the time of day you will not see the 0 in the far left side. Example; if the first two digits of your code is 02 you will scroll with the HR button until 2 appears on the display.).
  5. Press the AM-FM button to enter the code. The theft deterrent system will now be deactivated and customer code removed. The display will show --- and then change the clock.

E. Adding a Customer Code - with battery and ignition voltages applied and radio power off.

  1. Press and hold presets 1 and 4 for about 6 seconds until the display changes to ---
  2. Press the HR button until the display changes to 000
  3. Set the first two digits (01-19) of the code with the HR button.
  4. Set the next two digits (00-99) of the code with the MIN button
  5. Press the AM-FM button to enter the code
  6. When "REP" then 000 is displayed, repeat steps 3 through 5 before display changes back to clock. This confirms the customer code and activates the theft deterrent system. The display will then show SEC for secured.

F. Changing customer mode

  1. When changing a code in a unit that has already had one programmed, the original will have to be removed first. If the radio is unlocked follow step D to remove and deactivate the first code.
  2. Follow step E to reenter a new code.

Note: If the unit is in LOC the appropriate steps must first be followed

G. INOP second level lock condition

After eight initial failed unlock attempts, the unit will be in a second level lock condition and become inoperative for over 1 hour. Any further code inputs during this hour (or depressing any buttons) will cause the display or indicate InOP for about 15 seconds before returning to LOC.

The unit will still be inoperative. To reset to the normal locked (LOC) condition, battery and ignition voltages must be continuously present for over 1 hour continuously. Do not attempt any radio entries or functions during this time-out period.

After the unit is brought back to the normal locked condition, the correct unlocking procedures can be followed. Following every three unsuccessful entries the unit will return to the inoperative state (InOP) for another 1-hour period.

Obtaining factory backup code

  1. First, the radio display code must be obtained.
  2. After obtaining the display code, and having your authorized account number, call 1-***-***-**** or 1-***-***-**** with a touchtone telephone.
  3. A. Gm-dealerships -- when the computer prompts, enter the corresponding digit for your controlling car division preceeding your 5 digit gm-dealer code, then press *.

    1 - Chevrolet/Geo

    2 - Pontiac

    3 - Oldsmobile

    4 - Buick

    5 - GMC

    6 - Cadillac

    For example, if your gm-dealer code is 01234, and your controlling car division is Chevrolet, then 101234* would be entered.

    Note: if your Ac-Delco account number is ***** digits, first Press 9 then the first 7 digits of the account number, followed by an *.

  4. When prompted for a 4 or 6 digit code, enter the display code, then press *. The computer will respond with the factory backup code. Write it down. Reference "to unlock radio" and "to remove customer's code" to use the factory backup code.
  5. Another display code may be entered when the computer prompts. If you are done, simply hang up.
Customer: replied 9 months ago.
it doesn't show any number or LOC
Expert:  Ryan Schott replied 9 months ago.

disconnect the battery negative for three min key off then reconnect and see if it is the same

Expert:  Ryan Schott replied 9 months ago.

same?

Customer: replied 9 months ago.
yeah
Customer: replied 9 months ago.
i just remove the stereo, what chip i have to remove?
Expert:  Ryan Schott replied 9 months ago.

I work for General Motors we don't internally re-manufacture stereos. your vin is not showing me a valid RPO code for the stereo that year does your truck still have the RPO tag on it.

Expert:  Don 'Mo Lurch' replied 9 months ago.

since you have the Radio out, can you post the Part Number & / or Model Number on the case?