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Hi everyone,

I have a 99 suburban that will occationally not start due to the factory security system. The dealership said they'll need to replace the ignition switch, key, and a couple of other things (not the security module though according to the computer) to make it work. Although, the tech told me is is most likely a bad connection or key... I used my spare key for 3 days with no security light on the dash popping up, but it did today. So, I guess its a connection or the switch is actually failing. Anyway, the dealerships solution all totals about $500 and half a day... My other local mechanics say they cannot do it because it has to be dealer re-set...

I care nothing about the factory security that cuts power to the fuel pump (seems pointless anyway). Is there a way to bypass it? I hate to spend that kind of money on such an old vehicle for something seemingly minor.

Can I bypass it?
 

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ok, there are 2 ways to do this and they both are used by remotestart installers and 1 is much more reliable than the other:
the perferred way is to use a data module similar to the gmbp from bypasskit.com, however they also build for several other companies like dei, audiovox, codealarm etc. the way this would work is that the module would learn the passkey signal then send that learned data signal into the data link connector under the dash. you would have to hook up power, ground, data (which is purple @ the dlc) and then there is a ground when running wire and there is a couple of ways this wire can be used, I would use a relay that would power up off the pink ign wire at the ign switch. this relay would send a ground signal to this wire while the key is in the on position. the mod would then send the correct data signal to the bcm which would then tell the pcm its ok to send fuel to the injectors.
the second way is, when looking at the steering column wire harness for the ign switch there will be a set of 22 ga wires, yellow, black and white. these are the passkey wires. you will need to cut the yellow in half and strip back the black, strip the yellow going toward the ign switch. now using an ohm meter measure the resistance accross the yellow and black while the key is in the crank position. you will now need to go to radioshack and get a resistor in that value within 10%. ( if you have a dei dealer close by call them and ask if they have a spare vats pack, they usually are laying around). you will now wire that resistor accross the yellow that you did not strip ( the side away from the ign switch and the black wire. tape off the yellow side that you measured with. you will be able to start the truck at any time now.
ok, here is the reason why I would suggest the first way:
in the second method you will most likely have issues somewhere down the road and heres why. the resistance value will change with temp and humidity. these changes will make the bcm think the truck is being tampered with and go into disable mode and the theft light will be flashing. when this happens you will need to leave the ign key in the on position for 10-15 minutes till it stops flashig. when this happens you will need to turn the key off and then start the truck. I have seen this problem many times and have replaced that setup with the data module set up and never hear back from the customer about a no start problem. some installers have used the resistor system because of cost and yes it will work most of the time but when it does fail it really sucks.
the data mod will cost anywhere from $25-$50 but it is well worth it
 

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Can it be setup to be done permanently? I don't want Passlock any more ... I spent 30 minutes stuck yesterday before Passlock would let me start my 1999 Silverado. I already have LoJack; Passlock can go away! (It has been giving me problems since new!)
 

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Can it be setup to be done permanently? I don't want Passlock any more ... I spent 30 minutes stuck yesterday before Passlock would let me start my 1999 Silverado. I already have LoJack; Passlock can go away! (It has been giving me problems since new!)
yes it can be done permanently by either one of the procedures I listed above and as stated the superior method would be by using the data link mod even though there is a little more install work. by using the resistor method you are likely to have the same type of problem that you had yesterday. the passkey system can not just be removed because the bcm needs a password from the ign cyl in order to send an ok to the pcm to allow fuel thru the injectors.
 

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I know this is a old thread but I was looking for some answers because I have a second gmc/chevy truck with ignition issues. I have a 1999 chevy suburban 1500 and it was doing the whole cut off the fuel trick. The trick to it is when you put the key in only turn on to auxilary lights on the dash, the security light should be on but NOT blinking. Should start up with no problem. I have been doing it for three years now and it has not not started. Just picked up a 1999 GMC custom van and when you start it up the dash lights blink on and off for a few mintues. Was told the dealer could give me a new key fob and reprogram it, problem solved. Anybody know anything bout that?
 

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ok, there are 2 ways to do this and they both are used by remotestart installers and 1 is much more reliable than the other:
the perferred way is to use a data module similar to the gmbp from bypasskit.com, however they also build for several other companies like dei, audiovox, codealarm etc. the way this would work is that the module would learn the passkey signal then send that learned data signal into the data link connector under the dash. you would have to hook up power, ground, data (which is purple @ the dlc) and then there is a ground when running wire and there is a couple of ways this wire can be used, I would use a relay that would power up off the pink ign wire at the ign switch. this relay would send a ground signal to this wire while the key is in the on position. the mod would then send the correct data signal to the bcm which would then tell the pcm its ok to send fuel to the injectors.
the second way is, when looking at the steering column wire harness for the ign switch there will be a set of 22 ga wires, yellow, black and white. these are the passkey wires. you will need to cut the yellow in half and strip back the black, strip the yellow going toward the ign switch. now using an ohm meter measure the resistance accross the yellow and black while the key is in the crank position. you will now need to go to radioshack and get a resistor in that value within 10%. ( if you have a dei dealer close by call them and ask if they have a spare vats pack, they usually are laying around). you will now wire that resistor accross the yellow that you did not strip ( the side away from the ign switch and the black wire. tape off the yellow side that you measured with. you will be able to start the truck at any time now.
ok, here is the reason why I would suggest the first way:
in the second method you will most likely have issues somewhere down the road and heres why. the resistance value will change with temp and humidity. these changes will make the bcm think the truck is being tampered with and go into disable mode and the theft light will be flashing. when this happens you will need to leave the ign key in the on position for 10-15 minutes till it stops flashig. when this happens you will need to turn the key off and then start the truck. I have seen this problem many times and have replaced that setup with the data module set up and never hear back from the customer about a no start problem. some installers have used the resistor system because of cost and yes it will work most of the time but when it does fail it really sucks.
the data mod will cost anywhere from $25-$50 but it is well worth it
ok you say you recommend installing a DATA LINK MOD, could you give us a little more information? like the full product name, where one can find this product and what are we looking at in the way of cost for this product, I googled Data Link Mod and got a zillion products, none actually hinted at GM pass lock issues so we need more information if you got it? Thank you
 

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ok you say you recommend installing a DATA LINK MOD, could you give us a little more information? like the full product name, where one can find this product and what are we looking at in the way of cost for this product, I googled Data Link Mod and got a zillion products, none actually hinted at GM pass lock issues so we need more information if you got it? Thank you
That dude hasn't even logged in in 5 yrs. Better attempt somewhere else. Sorry I'm of no help.
 

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I know this is a old thread but I was looking for some answers because I have a second gmc/chevy truck with ignition issues. I have a 1999 chevy suburban 1500 and it was doing the whole cut off the fuel trick. The trick to it is when you put the key in only turn on to auxilary lights on the dash, the security light should be on but NOT blinking. Should start up with no problem. I have been doing it for three years now and it has not not started. Just picked up a 1999 GMC custom van and when you start it up the dash lights blink on and off for a few mintues. Was told the dealer could give me a new key fob and reprogram it, problem solved. Anybody know anything bout that?
Can you tell me why mine starts and runs just fine when its warm outside but when winter gets here it will not.Security light goes to blinking and it cranks and dies.
 

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ok, there are 2 ways to do this and they both are used by remotestart installers and 1 is much more reliable than the other:
the perferred way is to use a data module similar to the gmbp from bypasskit.com, however they also build for several other companies like dei, audiovox, codealarm etc. the way this would work is that the module would learn the passkey signal then send that learned data signal into the data link connector under the dash. you would have to hook up power, ground, data (which is purple @ the dlc) and then there is a ground when running wire and there is a couple of ways this wire can be used, I would use a relay that would power up off the pink ign wire at the ign switch. this relay would send a ground signal to this wire while the key is in the on position. the mod would then send the correct data signal to the bcm which would then tell the pcm its ok to send fuel to the injectors.
the second way is, when looking at the steering column wire harness for the ign switch there will be a set of 22 ga wires, yellow, black and white. these are the passkey wires. you will need to cut the yellow in half and strip back the black, strip the yellow going toward the ign switch. now using an ohm meter measure the resistance accross the yellow and black while the key is in the crank position. you will now need to go to radioshack and get a resistor in that value within 10%. ( if you have a dei dealer close by call them and ask if they have a spare vats pack, they usually are laying around). you will now wire that resistor accross the yellow that you did not strip ( the side away from the ign switch and the black wire. tape off the yellow side that you measured with. you will be able to start the truck at any time now.
ok, here is the reason why I would suggest the first way:
in the second method you will most likely have issues somewhere down the road and heres why. the resistance value will change with temp and humidity. these changes will make the bcm think the truck is being tampered with and go into disable mode and the theft light will be flashing. when this happens you will need to leave the ign key in the on position for 10-15 minutes till it stops flashig. when this happens you will need to turn the key off and then start the truck. I have seen this problem many times and have replaced that setup with the data module set up and never hear back from the customer about a no start problem. some installers have used the resistor system because of cost and yes it will work most of the time but when it does fail it really sucks.
the data mod will cost anywhere from $25-$50 but it is well worth it
 

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On my 99 silverado, I had the blinking security light, went into cut off mode.
There is a procedure, too restart. key to on 10 min, off 1 min, 10 min on, off 1 min, on 10 min, then off.
Got it home, found loose connection at the three wires, above key.
Took each wire, out of plastic block, slightly pinch the metal strip, closer, and fixed problem.
 
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