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 Ms. Wrench Your Own Question
Ms. Wrench
Ms. Wrench, ASE Certified Technician
Category: Chevy
Satisfied Customers: 554
Experience:  ASE Certified Tech, Engine Performance & Diganostic Specialist, Alternative Fuel Expert
9964578
Type Your Chevy Question Here...
Ms. Wrench is online now
A new question is answered every 9 seconds

trailblazer security light on car will not start

Customer Question

No Comment Added
Submitted: 9 years ago.
Category: Chevy
Expert:  Ms. Wrench replied 9 years ago.

Hello,

OK you probably just need to reset the passkey system. What you do is

1.turn the key to the start position (all the way forward) for 2 seconds.

2.return it to the run position.

3.leave it like that for 10 minutes-after 10 minutes the light should go off and you should be able to start the truck. You might have to do it more than once.

If that doesnt work out let me know. Or if you have actually changed the lock cylinder and are using a different key now also let me know. Any details will help.

Thanks for using JA

Ms Wrench

Ms. Wrench and 2 other Chevy Specialists are ready to help you
Customer: replied 9 years ago.
security light is on steady for over 15 min has not gone out yet
Expert:  Ms. Wrench replied 9 years ago.

OK then do you want to give me some details on the repair you just did-exactly what you replaced as in the lock and key or the electrical part, and why they needed replacement. In the meantime-disconnect the battery for at least ten minutes to let the computer memory clear, then you can try it again. But answer me back about the details so I make sure I'm telling you the right thing.

Thanks for Accepting!

Ms Wrench

Customer: replied 9 years ago.
ok here is what happened the car would not start, the speed om and tach go crazy when you try to start it i got it connected to a computer and got a u1000 class 2 serial communication problem and a b1372 device ignition #1 circuit low called a dealer they said ignition switch so i changed it no luck the lock cylinder and key are the originals. then i noticed the security light was on and here we are now
Expert:  Ms. Wrench replied 9 years ago.

Hello,

OK thanks. Are you disconnecting the battery? I'll get some more info now that I have that information-just let me know as soon as you try it again. That may take care of it since there was a serial comm code.

Let me know

Ms Wrench

Customer: replied 9 years ago.
ok battery is disconnected waiting 10 min
Customer: replied 9 years ago.
ok battery hooked up security light went out, tach and speed dials jumping around still will not start
Expert:  Ms. Wrench replied 9 years ago.

What is your votage gauge reading? Did you do the passkey reset 10 minute thing again or was the light out when you hooked back up the battery? And it is not turning over right?

Ms Wrench

Customer: replied 9 years ago.
light was out when battery was hooked up no it does not turn over i can hear a ie buzzing noise under the hood
Expert:  Ms. Wrench replied 9 years ago.
Is the buzzing noise just when you try to start it? What does your voltage gauge say? I'm thinking your battery might be low-is that possible?
Customer: replied 9 years ago.
the buzzing it happening while the gauges are jumping around the volt gauge looks to be around 10 to 12 checked battery earlier eye was green and seems to have good power i thought it might be that earlier put cables to it and nothing changed
Expert:  Ms. Wrench replied 9 years ago.

Right, but what I'm asking is do the gauges jump and the buzz happen when you try to start it? If so, go ahead and put cables on it again. Try to start it and if the light comes on go ahead and do the passkey thing. Let me know. I'm checking out why else that code would have been set except for the ignition switch in case none of this works out.

Ms Wrench

Customer: replied 9 years ago.
the gauges jump and the buzzing is heard while the key is in the run position
Customer: replied 9 years ago.
i can not put the cables on right now do you have any other suggestions or concerns
Expert:  Ms. Wrench replied 9 years ago.

Well I am thinking that perhaps replacing the igition switch was not the answer to your problems. There is a TSB for that vehicle that lists those codes and refers to a bad BCM-body control module. The code u1000 refers to serial data comm loss-that could point to any module-it just indicates a comm problem.

If you can get it scanned again let me know and I'll be glad to help. I also still suspect a ground problem or low voltage. Let me know tomorrow what you find out. Sorry we couldnt fix it tonight.

Thanks again,

Ms Wrench

Customer: replied 9 years ago.
ok
Customer: replied 9 years ago.
morning i connected another battery to the car no luck