Hi all,

I wanted to ask for a bit of guidance on my trouble shooting.

Early this week I noticed that my Security light in the gauge cluster was coming on, and staying on (not blinking) while driving around town. When I would stop and take the key out and start again, it would not always come back. If it did, it would come back on after a few minutes driving around town.

I did a quick search of here and came upon a thread that suggested that the weight of key-rings could be damaging the ignition lock cylinder Hall sensor. So the last couple days I started driving with only the ignition key only and the Security light has remained off while driving.

My questions are these:

• Is there a good way to tell if one of these two parts, the ignition lock cylinder or ignition switch, was the cause for my seeing the Security light coming on?
• Could the issue be with something other than the ignition lock cylinder or ignition switch?
• My 99 Blazer being 20 y.o., would it be a good idea to replace the ignition lock cylinder and the ignition switch (two different parts) as a preventative measure?
• If I were to get a new ignition lock cylinder, is it possible to have it modified to match my current key?

Thanks

P.S. I did find SwartLKK's excellent thread on the Anatomy of the Ignition Switch. I gave a lot of good information but I was not able to use it to answer my questions. https://blazerforum.com/forum/lighti...-light-102556/

 

Christine

As I am sure that you know, a solid security light indicates a fault condition and even though your key ring weight appears to be involved, there are other fault condition possibilities. There are quite a few gm specific OBDII codes for faults in the security system and since your wanting to confirm before any work, do you have access to a high end code reader that can pull Bxxxx and Uxxxx codes (BCM and module class 2 communications)?


George

 

In addition to my first post, A few more thoughts. Electrically there are three functions in the switch. Power routing through multiple contacts, the passlock sensor and the key in ignition switch signal. You have not mentioned any global electrical problems or starting problems/flashing security light so the first two may not be at issue but what about the door chime when the key goes into the ignition?


George

 

George,

Thanks for the ideas.

I have not seen the security light come on while driving since I removed the ignition key from the key-ring. This could be a coincidence.

I have not noticed any other electrical faults or issues.* I don't recall one way or the other about the door chime. Everything seems to be working fine at the moment.

As for taking OBD readings, was thinking this would be the perfect excuse to finally get a proper one. I was looking at the VIDENT iLink400 Full System OBD2 Bi-directional Scan tool. (https://www.videntstore.com/wholesal...scan-tool.html) I found it as one of the ones recommended by you and Les. Would you happen to know if it would help in this case? I also have a collision sensor going bad again so I thought it could help with confirming which of the two is going bad.

Christine

* OK There was one issue yesterday. While driving at highway speeds of a long grade my HAVC controls were having air come out of the wrong vents but that might have been a one-off thing and/or due to my vacuum hoses starting to leak which I'll check later with my vacuum pump. The HVAC system worked fine today in town.

 

Christine

That iLink 400 certainly seems like one of the better values in bidirectional scanning but I don't know if it will address these issues. I tried to look through the GM function list on their website but I am having trouble accessing the file. Les may be of more help on this question.

George

 

Thanks George.

Yeah, I've tried to check their specifications too. What would be nice, is if they published the list of all.of the errors they could read.

 

I finally got that spreadsheet to open. It just says say BCM with no DTC list and does not list class 2 communication codes so I am not sure what it can read.

George

 

I ordered the Vident scanner so I will be able to let you know how well it works.

 

Christine

Good luck with your new purchase, keep us informed.

George