Big issue with Anti-Theft system?

M

MrSteve

New member
Joined
Mar 17, 2018
Messages
11
Reaction score
0
Points
0
Okay so i bought a 99 sunfire 2.2L auto 4 door power options etc, for cheap. Anti-Theft light is on, and will not go out, car cranks but will not start....

I have tried the 10 minute cycle, multiple times, with and without the passlock plug hooked up under the ignition, with and without the 2200 ohm resistance bypass, and no matter what trick i Google and found and try, the light never flashes and never goes out. It just remains on solid.

Tried different coils, icm, plugs, wires. Not sure what previous owner tried but he seemed fairly mechanically inclined and just gave up and was about to scrap it.

Please help as the whole car is in mint condition except for this problem, my next step was going to be pulling out the ecm and inspecting it for corrosion etc...
 
Last edited:
Have you tried replaceing the complete ignition lock/switch assembly?
Have you checked the connections at the BCM for corrosion?
 
melsg5 said:
Have you tried replaceing the complete ignition lock/switch assembly?
Have you checked the connections at the BCM for corrosion?
Click to expand...

No corrosion on any connectors anywhere, pulled the ECM out today to inspect it and same, no corrosion.

Where is the BCM located on a 1999 because I cannot find it anywhere... I have taken apart the whole dash, removed passenger side air bag, the module by the driverside kick panel says ABS so im kind of lost where it would be

Edit: ignition lock/ switch assebly is opposite side of the key correct? If so no and there are what looks like factory installation markings on the casings and screws so it would seem as though it hasn’t been replaced
 
you looked behind the glovebox for the BCM?
sounds like you should try replacing the ignition lock/switch.
______________________________
 
melsg5 said:
you looked behind the glovebox for the BCM?
sounds like you should try replacing the ignition lock/switch.
Click to expand...

Yea no module there anywhere except the dome light/chime module.

New switch getting picked up sometime this week, will post results
 
Ok I picked up another dash cluster and ignition switch from a local parts yard, took them off myself from a 98 sunfire.

I’ve swapped over the circuit board from the donor dash cluster to my cluster so it has the same odometer reading, as the chip is built into the cluster it looks like.

Same results everywhere.... theft light stays on, does not flash, and will not go out after 10 mins, engine cranks but does not fire
 
melsg5 said:
back to your first post, you mention a 2.2K resistor, did you come up with that number by measuring with an ohm meter?
have you seen this link?
https://kingbain.com/how-to-permanently-disable-gm-passlock-system/
Click to expand...

Have looked at that link or one similar and that was a random value i tried based on some of the reviews i read/watched.

Reason i did this was an interesting thing/idea..... when i try to grab a resistance value off of the ignition side of cut yellow wire, i get nothing, no value at all when car is off or in run position! And when i test the wire on the side that disappears into the dash when cars off, i get a value of 4400, and when i turn the key to on, it jumps to around 12000.....
Also, Ground is fine i continuity check all metal around on the steering column/lock/wires to chassi so i dont think its a ground issue either....

Edit: I’m going to try and grab a resistance value off the ignition lock again just in case i was doing something wrong and try the 10 min cycle as well with a value if i do get one
______________________________
 
Ok I’m not getting any resistance value off of the ignition when on and continuity from its middle pin (ground) to the outside shell of it (also ground) is non existent.

I’ve tried to grab resistance value with the ignition anti theft module plugged in and unplugged from the vehicle harness, nothing...

I’m thinking this might be a problem? But even if it is wouldn’t I still be able to bypass it with a resistor? Or do i have to know what value to use? Cause if i bought a new key/ignition tumbler from local auto parts store its over $300 and “has to be programmed by the dealership” and it will have a different resistance value than my current one anyway?
 
there are videos from professional shops that do the relearn by leaving the key in the run position for 10 minutes until the light stops flashing, no dealer required.
the ohm test is supposed to show the resistance of the ignition switch assembly, nothing else, in the run position so if you get no reading the ignition switch is bad.
new ignition cylinder $174 not $300, watch the video on the link
https://www.autozone.com/interior/i...rt-ignition-lock-cylinder/646705_19254_0_1277
 
Is there any way i can avoid getting a new one of those, it wont be happening for a couple weeks until next paycheck...

Edit: I just remembered i have access to another 99 sunfire, so im going to pull the ignition lock cylinder out of it and re test. Will post results when i have some
 
Last edited:
take your ohm meter and measure the resistance before you pull the whole thing out
______________________________
 
melsg5 said:
take your ohm meter and measure the resistance before you pull the whole thing out
Click to expand...

Yup, will do! Doing it tomorrow morning so i will post results by the afternoon. Wish me luck lol
 
Car was dead it has been sitting for 2 years but with a jump fired up, ran for a second and then shut off with the anti theft light flashing..... perfect! Pulled the lock cylinder out and i snagged the coils and ICM as well...

Installed “new” lock cylinder in problematic sunfire, still, same problem.... cranks but does not fire.....
Anti-Theft light remains on solid, does not flash, and does bot turn off

Replaced crank position sensor, no results....

When i get home from work i’m going to pull the battery terminal off and sleep on it, re try again in the morning....

And i was able to grab a resistance value, so fingers crossed!!!!
 
Nothing, same as before, pulled plugs and tested for spark, check. Checked for fuel, its getting it, did compression test........

Oh boy, from passenger side to driver side (1-4) it got: 100,55,50,90.......

Shame, body of this car and all the electronics seem to work well....

Anyone in BC Canada want to buy a cheap Sunfire? Lol
 
you did this test with the throttle held wide open?
______________________________
 
melsg5 said:
you did this test with the throttle held wide open?
Click to expand...

Yes, pulled the valve cover off and tried cranking it, no movement and it has bent pushrods. I scrapped the car

Thanks for all the help along the way though
 
The ignition lock might be faulty. I would say that is your first step to look at replacing that part before you go tearing apart everything else.
 
You must log in or register to reply here.

Share this page

Back
Top