How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask goodwrench9124 Your Own Question
goodwrench9124
goodwrench9124, ASE Certified Technician
Category: GM
Satisfied Customers: 3432
Experience:  37 years of dealership exp. Ase Master Certified, GM Master Certified Tech. Awarded GM Top performer
5720312
Type Your GM Question Here...
goodwrench9124 is online now
A new question is answered every 9 seconds

2002 GMC: my security warning is on and my truck..even turn

Customer Question

I have a 2002 GMC Sierra and my "security" warning is on and my truck will not start. Will not even turn over, battery is good, (new) and fully charged.
Submitted: 7 years ago.
Category: GM
Expert:  goodwrench9124 replied 7 years ago.
Hello, and welcome. is the security ligh on steady? or flashing?
Customer: replied 7 years ago.

Flashing when I open the door.

 

Security light goes out when ignition key is set to first position, then the battery picture comes up.

Expert:  goodwrench9124 replied 7 years ago.
Ok, did this start of all of sudden? and do you have a aftermarket alarm system or a remote start on this vehicle?
Customer: replied 7 years ago.

Happened all of a sudden. I had dropped my keys on concrete.

No aftermarket alarms or remote start.

Expert:  goodwrench9124 replied 7 years ago.

ok, I suspect a bad ignition lock pass key sensor. I need you to try this. this will take 30 minutes, i recommend a battery charger if you have one. if the battery gets low this relearn wont work correctly. try this and let me know what happens.

 

  • Turn ON the ignition, with the engine OFF.
  • Attempt to start the engine, then release the key to ON; the vehicle will not start.
  • Observe the SECURITY telltale; after approximately 10 minutes the telltale will turn OFF.
  • Turn OFF the ignition, and wait 5 seconds.
  • Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes; the vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.
  • Important: The vehicle learns the Passlock Sensor Data Code and/or password XXXXX the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

  • Start the engine. The vehicle has now learned the Passlock Sensor Data Code and/or password.
  • Customer: replied 7 years ago.

    I am going to try this now

     

    Expert:  goodwrench9124 replied 7 years ago.
    ok, i will be here, just let me know what happens
    Customer: replied 7 years ago.

    I wrote down the instructions, and followed them.

    My engine light stays on?

    Expert:  goodwrench9124 replied 7 years ago.
    your engine light or your security light?
    Customer: replied 7 years ago.

    With no key in the ignition and door open, Security light is flashing. Close door and Security light is off.

     

    With key in the ignition in the on position, battery and engine light up.

    Expert:  goodwrench9124 replied 7 years ago.
    Ok, do you have a scan tool or a code reader to check for codes?
    Customer: replied 7 years ago.
    No I don't. Do you think it is time to get one?
    Expert:  goodwrench9124 replied 7 years ago.
    if you are wanting to try to repair this your self, a code reader would be a plus. we need to know what fault code is stored in the system?
    Customer: replied 7 years ago.

    My 2002 GMC, is it ODB ll compliant?

    Looks like I can pick one up that would look for the problem and reset the engine light.

    Customer: replied 7 years ago.
    Well, I am on my way downtown to pick up a code reader. I will get back to you.
    Expert:  goodwrench9124 replied 7 years ago.
    ok, let me know
    Customer: replied 7 years ago.

    Hello Hello, Now I have a fancy $200 code reader that can reset a fault. Found no faults to reset.

     

    What I did do is followed the steps you had laid out to reset "security", that did not work. I decided to leave out step 2 (attempt to start engine). The first time I did that,

    yo0hooooooo my truck started.

    Expert:  goodwrench9124 replied 7 years ago.
    Ok, so is the truck starting ok now and no more securtity light coming on?
    Customer: replied 7 years ago.

    I remembered a friend of mine who had the same problem around 6 months ago. When I read him your instructions, He said forget step 2.

     

    And yes my truck starts every time. As I had mentioned earlier, No faults were read by the code reader.

    Expert:  goodwrench9124 replied 7 years ago.

    Great!! Good news indeed. hopefully you wont have any more problems!!!