If Chevrolet Suburban Won't Start It ...

If Chevrolet Suburban Won't Start It Could Be Security Feature Issues

There are 219 comments on the Associated Content story from May 5, 2009, titled If Chevrolet Suburban Won't Start It Could Be Security Feature Issues. In it, Associated Content reports that:

Many GM model cars and trucks are equipped with what is known as the Passlock feature which is a factory based security system that shuts down the fuel lines when an attempt is made by a thief to steal the vehicle.

Join the discussion below, or Read more at Associated Content.

robertguero

Conway, AR

#22 Jun 4, 2010
Chaz wrote:
I don't have this problem on my 97. but did anyone try to disconnect the hood light? You never know. But it would be good to know if it worked or didn't. If I find out anything, I'll post it.
1997's dont come with immobilizer.
PaT

Lake Luzerne, NY

#23 Jun 10, 2010
Roberto your installsupport.com is not a valid site. can you give that to me again?
robertguero wrote:
<quoted text>NO THE PASSLOCK 2 ANTI-THEFT System CAN NOT BE REMOVED ON ANY VEH. IT IS AN INTEGRATED SYSTEM. You can use a bypass module BUT you must have keys that are already programmed to the veh to install a bypass module.
All of the problems in these post, if your security light is "ON" or flashing, is the transponder is not being read correctly. If you try to many times to start with wrong transponder signal (chip in key or ignition lock) being read the system will shut you out for a period of time. Leaving the key in the ignition with it "ON" for a period of time will sometimes reset the code. Most of these the ignition lock needs to be replaced or the system bypassed. A simple resistor on some systems can be used to bypass. most others need a module and programmed keys to bypass the factory immobilizers. Any alarm shop knows how to do this. Stop going to mechanics, they have no idea. I have plenty of info at installsupport dot com.
Paul

Wauconda, IL

#24 Jun 19, 2010
I have a 1999 Suburban, security light stays on vehicle will start and quit, I have replaced lock and cylinder, passkey sensor, checked all wires and connectors, have not replaced passkey module, when ambient temp is below 80 inside vehicle, vehicle will start everytime, any hotter than that...it will start/quit/security light. I leave the windows open for 1 min. to cool interior and vehicle starts up...the rear door seals are leaking rain onto carpet and the interior is very humid...hot and humid interior = no start, I beleive it must be a connection issue, I have not had to leave the key in the on position to reset the system, only roll the windows down for a short time before it will start
mya

Sherman Oaks, CA

#25 Jun 21, 2010
i have a 99 suburban and it cut off while i was driving on the freeway. a guy changed my fuse under the hood and it ran for two days the it just cut out again. i checked all the fuses again and still it wont start it sounds like its out of gas when i try to turn it on but it does have gas in it. i first heard it was the fuel ppump but it wasnt then i heard it was my crank sensor but i had that changed now their saying it my not be getting any spark or fire to it ?????? does any one else have and answer with what i should try
chadillac469

Wichita, KS

#26 Jul 4, 2010
ive got the prob with it not firing up whhen evr it rains first time the batt had 2 dead cells now its doin it again an its not gettin fire at all the ig mod is good so if this hapens again i recomend that im an all you trade them in cause this is goin to be a constant prob an chevrolet ( gm) dont care they got there money
Nate

Philadelphia, PA

#27 Jul 18, 2010
I have a 99 Yukon that had this problem and here's my solution. The Passlock system measures the resistance across a GM key to determine whether its the actual key or a screwdriver jammed in the ignition. If the resistance is wrong, the Passlock disables the fuel pump so the car can not be stolen. It resets in 5 minutes and the car would start. But for those 5 minutes it didn't matter how many times I tried. I had a Goodwrench shop that told me it was the fuel pump, and so I replaced it.(Did not solve the problem). After more research I came to the conclusion it was the Passlock system.
MY SOLUTION: I installed a remote starter bought off Ebay that had a bypass module for a GM. It puts a variable resistor in the ignition line that tricks the Passlock system into thinking that a key is always in the ignition. I haven't had the problem for over 4 years now and I have a remote starter. Cost $25
ScottFunkhouser

Fenton, MO

#28 Jul 18, 2010
I recently swapped an '01 4.8L into my '85 Blazer. I received quite the education on the Chevy VATS(Vehicle Anti-Theft System). I believe this information is pertinent to all GM's SPFI engines ('00 and up). This is what I can tell you:

1.If you turn your key on and the engine won't turn over it's not the Security System. The VATS will allow the starter to engage, and the engine runs normally for 3 seconds then die.
2.The ECM (or PCM) has ultimate control over whether the engine runs or not, and it makes its decisions based on inputs from various sensors. For instance, if the computer senses the engine's water level is dangerously low it will shut down the injectors and allow the engine to just barely limp along (This is completely IDIOTIC because if you are forced to continue driving to safety the lean condition in the engine causes it to run EXTREMELY HOT!!! Any GM engineers reading this, IT'S FRICKING STUPID!!! FIX IT!!!)
3.There is a website, LT1swap.com , that will program the VATS out of the ECM, as well as make some performance enhancing adjustments (more power, shift kit, bigger tires, etc...). It's VERY inexpensive and the tech that does the programming is very knowledgeable and helpful.

I posted this so that those who are having problems will be able to eliminate the VATS as a possible culprit. I am not a GM mechanic, nor am I a professional mechanic. I am just a NAVY avionics tech with a little experience in the subject, so don't sue me if I'm wrong, just trying to help.
ScottFunkhouser

Fenton, MO

#29 Jul 18, 2010
This is an economic and potentially viable solution. In fact I researched it as a possible solution to a VATS problem I was having doing an engine swap. My only question was this, and it became the reason I went another route: when you get in the car to drive you have to put the key in the ignition to shift out of Park. Does this not transfer control of the PASSLOCK system back to the ignition switch? Honestly I don't know the answer, but am curious to know.
ChrisH

Charlotte, NC

#30 Jul 26, 2010
I am currently experiencing an intermittent no-start problem with my 01 Suburban.
It will crank & run fine the first time in the morning, but when I get to work & turn it off & try to restart, it will not turn over.
Once it cools down, maybe 15 min, sometimes up to 4hrs., it will restart.
When it finally does restart, I can turn it off & re-start numerous times in a row, but after 5 min drive, nothing.
I always have voltage,(lights,a/c fan, windows, locks, etc., all work.) Just won't turn over.

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Justin

Carrollton, GA

#31 Aug 14, 2010
Nate wrote:
I have a 99 Yukon that had this problem and here's my solution. The Passlock system measures the resistance across a GM key to determine whether its the actual key or a screwdriver jammed in the ignition. If the resistance is wrong, the Passlock disables the fuel pump so the car can not be stolen. It resets in 5 minutes and the car would start. But for those 5 minutes it didn't matter how many times I tried. I had a Goodwrench shop that told me it was the fuel pump, and so I replaced it.(Did not solve the problem). After more research I came to the conclusion it was the Passlock system.
MY SOLUTION: I installed a remote starter bought off Ebay that had a bypass module for a GM. It puts a variable resistor in the ignition line that tricks the Passlock system into thinking that a key is always in the ignition. I haven't had the problem for over 4 years now and I have a remote starter. Cost $25
Hello Nate,

Do you happen to have a brand name for the remote starter and bypass that you bought and who you may have bought it from. I am having the same issues with stalling and security light coming on and would like to go the route that you did since it seemed to work and I will keep my fingers crossed. If you wouldn't mind letting me know the model number of the remote starter and bypass thanks.
Bertha

San Diego, CA

#32 Aug 17, 2010
Our problem was solved....after four months, four trips to two different dealerships, several trips to my local mechanic, a new fuel pump and a new BCM. After all of that, it turned out to be our "Powertrain Relay" that was shorting out and causing the engine to turn over but not start. Whenever this happened, the low fuel light would display even though the tank was full. It had also started to die on me when idling. Once we replaced the Powertrain Relay we've had no problems for almost 3 months. Upon examining the old part, it was black and singed around the prongs -- obviously had been shorting out quite a bit. The service manager said this was a very unusual issue, so it might not apply to your vehicle....but I hope this info can help some of you out there.
kendall

Murfreesboro, TN

#33 Sep 11, 2010
I have had this problem with many of my Gm vehicles. Certain years of Gm products that have the passlockII systems. With this de-mobilizing system the contacts inside of the ignition system has to read current through the key. Although my key's weren't "chip" keys they still have to have the voltage read through them. When the contacts inside the ignition become wore to the point they will not conduct any longer the system assumes there is no key and the vehicle is being started by other means thus engaging the security feature.This is also the reason it gets worse and takes longer to disengage the security after time, the contacts only wear more over time taking longer to read the correct resistance values through the key. Many times the contacts can be cleaned by electrical cleaner being sprayed into the switch then pushing the key into the ignition multiple times. Do not attempt to start until you are sure the cleaner is dry. Blowing the cleaner out with airduster can help speed up the process. If this does not work you will more than likely need to replace the ignition switch. If your vehicle doesn't start altogether you may be having an issue with the computer itself.The best thing to do would be to try the cleaning method to see if it helps at all, it is the cheapest route to start with. I hope this helps, It has been a lifesaving bit of knowledge for me.
sramos

El Paso, TX

#34 Sep 11, 2010
I have a 2004 Suburban. I have had this issue with the alarm system for about 2 years now. It started out with just resetting the alarm, open door;lock doors;close the door;wait till alarm light stops flashing;wait 30 sec; then disarm; and truck should start....this only worked the first 2 times. I have had instances where it had left me stranded for up to 3 hours! I am really considering just getting rid of it and filing a complaint. It ridiculous that we have to go thru this and not have an answer. Vehicle is way too expansive to have such petty malfunctions
chicdriver

United States

#35 Dec 6, 2010
Drive a 99 and have to run out about 20 min prior to needing to go anywhere to make sure it will fire up. Much worse in cold weather, turn the key, if the Security light blinks I know it will not fire, however if I turn it and it goes solid, I'm good. Very annoying. Dealerships and mechanics don't seem to know what is wrong. Has new fuel pump couple years ago and new drive shaft last winter.
Frustrating, other than that, love the car, when it runs.
S Delp

Philadelphia, PA

#36 Dec 10, 2010
My security light blinks and won't allow the truck to start and I have to sit 15 to 20 minutes for it to start, I took it back to Stock Burgers where I bought it and said it was the ignition switch, They replaced it and cost me $450.00, between parts and labor,, Well now 8 months later it is doing it again. So they replaced it again,, Cost was the same.. Well here again it is still doing the same thing,, Not every time I start it but enough to annoy you,, I would say, at least 18 to 20 times a week. I don't have $450.00 each time to get this problem fixed, Why it is constantly doing this,, and Why is this a temporary fix? What can I do about this problem? It isn't like I can afford to just go out and buy another car. I don't have the time just to sit that long, and constantly be late for work.
Why can't they just recall and fix the problem? This shouldn't keep happening,, Yeah, they tell you not to have anything hanging on your key ring to pull on the key inside the the ignition, Well the only thing I have it the remote and it still does it. Well Chevy,, What excuse can you come up with now? Maybe an electrical problem? Any suggestions? Chevy owner not happy and broke from constantly fixing it.
liner

Bronx, NY

#37 Dec 10, 2010
S Delp wrote:
My security light blinks and won't allow the truck to start and I have to sit 15 to 20 minutes for it to start, I took it back to Stock Burgers where I bought it and said it was the ignition switch, They replaced it and cost me $450.00, between parts and labor,, Well now 8 months later it is doing it again. So they replaced it again,, Cost was the same.. Well here again it is still doing the same thing,, Not every time I start it but enough to annoy you,, I would say, at least 18 to 20 times a week. I don't have $450.00 each time to get this problem fixed, Why it is constantly doing this,, and Why is this a temporary fix? What can I do about this problem? It isn't like I can afford to just go out and buy another car. I don't have the time just to sit that long, and constantly be late for work.
Why can't they just recall and fix the problem? This shouldn't keep happening,, Yeah, they tell you not to have anything hanging on your key ring to pull on the key inside the the ignition, Well the only thing I have it the remote and it still does it. Well Chevy,, What excuse can you come up with now? Maybe an electrical problem? Any suggestions? Chevy owner not happy and broke from constantly fixing it.
What you need is a mechanic that knows how to diagnose your security system.
JOE BOB

United States

#38 Mar 11, 2011
Bertha wrote:
We started having this same problem about 2 months ago with our 2002 Suburban. The car has roughly 84,000 miles and has been completely reliable up until now.(We are original owners) Intermittently, the car turns over but won't start. It always seems to start up later after sitting for awhile. A local service station had it for 4 days and finally got it to malfunction but received no error codes on diagnostic computer. Dealership had it for over 2 weeks and could never get it to malfunction, and never received an error code on the diagnostic computers. They said they manually checked everything in the fuel chain and could not find any problems. Dealership said that if it was a security system problem, they should have received an error code. They also said there was nothing in their dealership database of shared information addressing this issue. Unfortunately, I never paid any attention to the security light before now. When it starts acting up again (as I'm sure it will), I will see if the above-recommended procedures work for me to get it started. Can't anyone at Chevy investigate this issue??
What was the feul level when it failed?? I have a 2003 that when the tank gets lower than about 1/4 it doesn't like to start. Next time it fails, check out the level and if it's kinda low,add some fuel.
scott

Las Vegas, NV

#39 Mar 22, 2011
okay ive got the 1999 chevy sub 5.7 liter lt i just replaced the fuel pump,at 212,000.miles after driving it while the pump was going out for 5 months. found one online for 50 dollars in cluded in the price was shipping !! difficulty level my wife helped me ... Easy to do. So the whole time this was going on ive got the security light flashing .. Hot r cold its still does this, every so often ill try to start he truck when ever after a drive, long or short, or at its first start of the day .. okay so i hear all the things, fuel pump prime, a clicking in a silver box just under the dash bolted to the steering bracket on the left side..? what is that ? and then ill look up at the dash and the light is blinking!!!! so okay i dont have original keys but i dont think its chipped or works that waya anyhow and i dont have a remote for opening the doors.. now the onlything ive been able to try that i dont get much responce from doing is unpluging , battery, computer, that clicking shiny box, turn the key back wards and wait , well the only thing to do is turn the key off and on some times in 1 min, some times up to 20 mins or 30, it will turn on then, but what can i do for this ???
Justin

Carrollton, GA

#40 Mar 22, 2011
Hello Scott,

This is the bypass unit in your suburban. It is the security feature that is messing with you. I was going to replace my fuel pump since this is what my mechanic said to do but it is definitely electric with the computer system. If you go to this website and follow the instructions there it will help alot. That is where I went and once the security feature does this to me I follow the instructions and works like a charm every time. Just a little annoying and a little time consuming but I am not going to put a new computer and ignition in the vehicle to fix it. Here is the link. Hope it helps you out. http://gmcowners.com/gmc-forum/showthread.php...
Diego

Wantagh, NY

#41 Mar 26, 2011
I tried many things posted above. I change the 2 batteries in the truck. Changed the starter and still had the same problem. My brother works at a shop. They work with alarms so I asked him the question. He said that it could be my after market electric starter or alarm. He came over took the electric starter and the light went away. So did the not starting issue. The problem no I have is that I think the alarm was always on(security Light) it shorted my starter. I replaced the starter but the cable from the batter to the starter is having problems. The security light went away hopefully changing the cable will work. Not sure if the two problems are related or if one caused the other problem. I WILL SOON FIND OUT.

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