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Security Override

Discussion in 'General Chevy & GM Tech Questions' started by BDash, Aug 30, 2009.

  1. BDash

    BDash New Member

    I had a problem with my low headlight beams shutting down with some steering wheel positions/tilt. I found 2 corroded and loose wires at the multiswitch and attempted to reconnect them (not sure if they have good connection yet..difficult to reach, etc) Anyway, now the truck won't start..security system has it shut down. Security light stays on, cranks great, then won't start.

    Any thoughts.
  2. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Try a reset. Make sure your battery is FULLY charged, all accessories off.

    Password Learn Procedure For Anti-Theft System (5.0L, 5.7L & 7.4L)
    1. Password learn procedure must be performed if Vehicle Control Module (VCM), passlock module or
    passlock sensor is replaced. A password is communicated between VCM and passlock module to provide
    engine operation. If VCM is replaced, the VCM must learn the password from the passlock module.
    2. Attempt to start engine. Engine will start and then stall. After engine stalls, leave ignition on for 10
    minutes. After engine stalls, the SECURITY indicator light will come on for 10 minutes and then go off.
    The SECURITY indicator light is located on upper right corner of instrument panel, just above battery
    charge indicator.
    3. After SECURITY indicator light goes off, turn ignition off for 30 seconds. Attempt to start engine and
    then leave ignition on. After engine has stalled, leave ignition on for 10 minutes. SECURITY indicator
    light will come on for 10 minutes and then go off. After SECURITY indicator light goes off, turn ignition
    off for 30 seconds.
    4. Attempt to start engine and then leave ignition on. After engine has stalled, leave ignition on for 10
    minutes. SECURITY indicator light will come on for 10 minutes and then go off or until DTC 1630 is set
    in VCM.
    5. Turn ignition off for 30 seconds. Turn ignition on and wait 30 seconds. Attempt to start engine. If engine
    starts, password learn procedure is complete. Ensure DTC 1630 is cleared from VCM by turning ignition
    off for 30 seconds and then turning ignition on again. If DTC 1630 is not cleared from VCM, perform test
    procedures for DTC 1630 and repair as necessary. See appropriate SELF-DIAGNOSTICS article in
    ENGINE PERFORMANCE.
    6. If engine does not start, ensure procedure was properly followed. If procedure was properly followed,
    check for any DTCs. If any DTCs exist, perform test procedures for specified DTC and repair as
    necessary. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
    NOTE: Ensure battery is fully charged before proceeding. Performing this
    procedure will cause a Diagnostic Trouble Code (DTC) P1630 to be set in
    the VCM. It will be necessary to use scan tool to check for DTC P1630
    when performing this procedure. Ensure steps are followed in correct
    order, or procedure may need to be repeated.
    NOTE: DTC 1630 will be set in VCM as result of this procedure. DTC P1630 may be
    cleared from VCM by turning ignition off for 30 seconds and then turning
    ignition on again.
    1999
  3. BDash

    BDash New Member

    Thank you, I tried something similar, but these are better instructions. I'll try it now and let you know.
  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    You may have to do 4 resets to get it to go. Remember each one is 10 minutes and an engine crank. A less than perfect battery will go dead after an hour and then you have to start all over so a trickle charger helps in this situation. Good luck!

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