2007 Chevy Tahoe Service Theft Deterrent System

[Chevy85]

I have a 1992 Chevy p-30 step van...
Hasn't been running for a while ...
Changed battery and attempted to start and got a back fire ,and shut off... Not sure if its a compression issue or needs a full tune up ( spark plugs,gaskets,crab , wires&boots....

[carriedi]

If you had a backfire it means you had fuel and spark. Maybe not when you need it but at least it's a start.

the first thing I would check is spark. Take off the coil wire from the distributor cap and place it somewhere close to a ground. Crank the engine over and watch for spark jumping from the coil wire to ground. If there is no spark of there is poor spark or the spark is not consistent with the engine cranking I would look at your distributor. If there is good and consistent spark I would check fuel next. Since it hasn't run for a while, I would spray some carb and choke cleaner down into the throttle body. Then crank it again and see if the engine would start on the fuel supplied by the carb and choke cleaner. Carb and choke cleaner has enough fuel properties to start an engine. Don't use starting fluid. It's a little too hot. Don't have anything over the throttle body except for the air cleaner because if you have a backfire up through the throttle body you could have a fire. having a fire extinguisher close by would be nice just in case. So, be cautious. If the engine starts and then dies, that means it runs on the fuel you supplied and died when the fuel ran out. You will need to check your fuel pressure and check for injector pulse. If the engine still doesn't start and run for a little while, then I would start checking compression and stuff like that.

was the van running normally when it was parked?Or was it not running so it got put on the side? How old is the fuel in it? How long has it been sitting around? How many times have you tried to start it? Is the engine cranking over normally for that engine or is it cranking slowly? What engine does it have in it? Have you owned this vehicle and know it's history or did you just buy it from someone that said it's been sitting around for a while? Let me know as much about the vehicle as you can please...

[Guest]

Service Theft Deterrent System Dash DRO and Light are displayed, vehicle will not start. I have checked all the fuses, Tried the 10 min 3 times bit, tried the disconnect both battery leads and hold together for 40-60 seconds and nothing.

[carriedi]

If you have done all that, (https://www.youtube.com/watch?v=PVrJWz-XZ1Y) then you might need to hook up to a GM scanner with theft deterrent communications. See it there is a code for not recognizing the key. See if there is good communication from the theft deterrent module (the part that goes around the key) and the BCM. it could be a bad key module. When the key it turned to start the vehicle the transponder in the key is energized by the exciter ring coil that goes around the key. the key then sends out a signal that the system sees and checks if it's the correct signal to allow the vehicle to start and run. Sometimes the exciter goes bad.

Try other keys.

Verify fuses just in case. underhood fuse box: DLIS #34 and SEO B1 #52. Behind lower left of dash fuse box: DIM, BCM, DDM, DSM, PDM. just to be sure.

[Hector]

Wheels locking up reduced engine power,stabilitrack light on wont turn iff or on

[carriedi]

you should have your vehicle scanned. verify that the throttle sensors are reading correctly. Possible abs codes too.

reduced power is usually from the throttle body/throttle pedal system problem. Since the computer can't tell what is actually bad it reduces power so you shouldn't have an accident but can get it home or to a shop.

for the locking up check that the wheel sensors are all working okay

[Guest]

I think my 2000 Chevy tracker won't start because the immobilizer has been activated how can I start it my fab is broken and the key I have doesn't have the chip

[carriedi]

you should hook up a scanner and see what codes are stored. A good scanner will give you the passlock codes if the wrong voltage is seen for the resistor. You can crank the engine and see if the computer sees the engine rpm. Then see what you look for next

Is your security light flashing on the dash? If it is then you're probably right the passlock isn't allowing the engine to start.

If the security light is not flashing then you need to look at everything else that could cause a crank no start condition. (it does turn over when you turn to the start position right?)

Tell me exactly what is happening when you get in the vehicle to start it up...