Help!!

[noJeepshere]

the other day my 99 yukon wouldnt start for ten minutes. i turned on the rig and turned it over, it caught, ran, then died in about 2 seconds. i noticed the security telltale light in the dash was on, and as long as it was, the yukon wouldnt start. after several minutes the light went out and the truck ran fine. for a couple days it was fine, then it did it again and now the light stays on every time for 5-10 minutes. it has an aftermarket alarm installed by a previous owner, but i dont use it. any idea anyone, what could be wrong? its starting to drive me nuts.

 

[Jason4x4]

try a different key, it could be a bad key.

 

[NEK5]

When I was having some problems with our 99 burb, someone mentioned something about the security light causing issues. Do a search under my name for burb electrical issues.

 

[noJeepshere]

oh yeah...

the alarm system is a python, i dont know what else about it.

 

[Thunder]

Get some electrical cleaner and spray it on the Key and put it in and out of the ign switch. Wipe the key off with a rag and do it again. The contacts are prolly just gummed up with something. I have had that happen to me a few times with newer chevys and cleaning things up always worked for me. My wife and daughters usually drove my newer cars. Who knows what kind of crap get all over their keys in their purses. But what ever in in the bottom of their stuff bags ends up all ove the keys.

 

[readymix]

If the security light is coming on then it has to do with the BCM.
The key will not cause this either. Some people think that the GM keys have some RFID like thing in them....not the case. The sensor behind that thought is located in the key cylinder. When you rotate the key the sensor poles line-up and send the correct signal to the BCM.

Since you got the light on the DIC that means that the BCM got a fault code. GM can read it with the TECH II. It is not stored in the ECM and is not an OBD II code so don;t bother with Auto Zone.

Chances are that the cylinder is faulty or the alarm wiring has caused a fault in the wiring to the BCM.

 

[84zz4ss]

Relatively common failure. Probably a B2960 stored your security voltage is not the value learned by the theft module. Plan on buying a lock cylinder housing. This is where the security voltage drop takes place. On 99 modelyears it is also common to have to replace the ignition switch assembly. Not the lock and key but the switch and electrical harness.

Get the code scanned and shoot me a pm.

 

[noJeepshere]

problem solved!!!

I got online and called python to see what they said. the rep told me their security systems disable the starter, whereas i was able to turn the engine over but not run. he said that i could just unplug the brain for the alarm and that would completely disable the alarm. did that and no issues now. but now, strangley, i have no keyless entry. oh well, i can drive it! thanks for your help guys.

 

[Thunder]

If the security light is coming on then it has to do with the BCM.
The key will not cause this either. Some people think that the GM keys have some RFID like thing in them....not the case. The sensor behind that thought is located in the key cylinder. When you rotate the key the sensor poles line-up and send the correct signal to the BCM.

Since you got the light on the DIC that means that the BCM got a fault code. GM can read it with the TECH II. It is not stored in the ECM and is not an OBD II code so don;t bother with Auto Zone.

Chances are that the cylinder is faulty or the alarm wiring has caused a fault in the wiring to the BCM.

Relatively common failure. Probably a B2960 stored your security voltage is not the value learned by the theft module. Plan on buying a lock cylinder housing. This is where the security voltage drop takes place. On 99 modelyears it is also common to have to replace the ignition switch assembly. Not the lock and key but the switch and electrical harness.

Get the code scanned and shoot me a pm.

Mabe so guys but all the Chevys/GM I have had (93 and upto 2002)with the seceurity system always worked after I cleaned the Ign switch and Key.Never had to replace anything. Clean key and ign switch... Light goes off ... car starts. No problem. Works fine till someone inserts key with mascara, makeup, or some other woman stuff all over it.

__________________

 

[noJeepshere]

Works fine till someone inserts key with mascara, makeup, or some other woman stuff all over it.

__________________

i cleaned the contacts too and that seemed to help with smoothness in and out of the keyhole. and fortunatley im the only driver so i dont need to worry about woman stuff getting all over it.