starting issues

[MetalStorm]

so I guess I spoke too soon. I went about a week and a half with no starting problems. Then today it wouldn't start. So I turned the key to the on position and left it there. The "security" light went off after 4 minutes, and I turned the key and it started right up. So what do you think? Passlock sensor? Ignition switch?

 

[99yuko]

Ok, my 99 Denali is going threw a similar deal. 2 weeks ago today I replaced the fuel pump. The reason is when I would fill my take, the fuel would spill out and all over the top of the tank. Once I had the take out I noticed the retainer nut thingy was completely loose(off) and the whole thing was actually just bobbing there. I installed my new pump, harness, gasket... (after I got the retainer nut on all the way I bent the tabs out to futher retain it). I filled the tank up, it worked, the gauge worked all was good.

Fast forward to today and 600 miles away from home. As I tried to start my Yukon, it started ran for no more than 1 second then it stopped. It did that the 6-10 times that I tried. So my daughter and I had to catch the shuttle from the Mcdonald house to the hospital.(son has leukemia, last round of chemo, is in remission) I left hospital and walked to a fuel station and got a 2 gallon gas can and walked back to truck. It started right away. I returned to the station and filled the truck up, it only took 15.9 gallons??? I believe its a 30gallon tank. My fuel level gauge works intermitenly so I had no way of telling.

I am torn, i have heard that it could be my new pump, or the passlock, sounds like the passlock to me. I have issues with the steering column(replaced the tie-rods, pitman, idler arms, upper ball joints, swaped steering gear, and still have a shit load of free play in the wheel and it makes noises when i turn it.

Any Ideas.

 

[Bitsman]

My story.. hope it helps

I know I am a little late to this conversation.. But here is my Story..
99 Tahoe.. 154,000 miles.. 4 dr, 4x4.. 5.7 liter... Given to me by my oldest sister Boyfriend. all it needed was a set of tires.. Traded my old Caravan to a local tire shop for a set of what look like brand new take-offs.. Ran great for about 2 months.. Then the problems started... Would not start so i replaced the Battery.. began starting fine and all was well for about a month... Then it just stop starting again... Sometimes it would jump.. other times it would not... Sometimes it would just start as it was supposed to.. Other times just one click when I turned the key... Replaced the Starter.. Everything was fine again for about a week... then went back to the one click when you turn the key... Took Starter back off and to get tested.. tested fine.. reinstalled starter and it started right up and was good for about a week.. Then no start again.. Started checking wires around ignition switch.. sometimes they would test good then other times they would seem to test bad... Figured best to replace ignition just to be safe... After replacing ignition.. still would not start... Just one click when key was turned to start.... That was last night... Did some more looking online and thought it might be a battery cable problem now.. spent this am cleaning both pos and neg cables with solvent and wire brush this am... put it all back together and it started right up... Of course it has only been about 7 hours so far so I am still not sure if this is an actual fix yet... Moral of my story.. If you are having similar troubles... Really clean your battery cables first of all....

 

[MetalStorm]

Sounds like your problem might be of a different type. The issue we are having the motor would crank but would not get any fuel.

I did a little networking, and through a friend of a friend I obtained from GM a step by step and diagram of the passlock sensor replacement and PCM re-learn.

If anyone is interested PM me and I will email it.

 

[wpnzrule]

This may be silly, but seeing that the pass lock reads the resistance on the key. What are the chances that its not the sensor but the key?

 

[MetalStorm]

Thats a good question and I never really thought of that. But I could see a sensor or ignition switch going bad before a key would. That is, if a key CAN go bad. I'll look into that.

 

[TheBeast99]

this is definitely something i'm gonna get ripped out of my truck when i get the spare chance. i mean really, if the theives wanna get my truck, they'll make sure they get it - even if it's with a flatbed! lol
so screw my key not being the right resistance according to the computer. if i want to start my truck, no damn key sensor is gonna stop me!

 

[MetalStorm]

So this week has been a disaster trying to get the hoe started. Everyday I had at least one difficult time starting it, and I even had to get a ride home from work one day.

Met a guy through a friend of a friend of a friend, who was a GM mechanic for 30 years. He came over and hooked up his GM scan tool and found a "communication error" between the Theft Deterrent Module and the PCM. This module located under the dash has 2 power leads going to it from the passlock sensor. They get their power from the # 4 and # 21 fuse located inside the driver's door. This module is also grounded in 2 places, 1 on the engine block behind the alternator, and 1 deep in the rear of the block down by the firewall. All of my connections seemed to be good. We cleaned them up anyway and haven't been able to reproduce the problem since then. The strange thing is the Theft Deterrent Module or PCM have not saved any trouble codes in their histories. Even he was confused as to why we got that error, but there is no code stored.

I also cut a new key for the hell of it last week but that didn't prevent the problem from occurring during the week.

So since this past week I haven't really done anything other than the ole "tap test", and yank on some wires and connectors. I have my scan tool hooked up so now every time I start the truck, since it has been an intermittent problem, hopefully I will catch it throwing a code and try to narrow this down more.

BTW.....i was told bypassing the theft deterrent system is not an option, as it may throw codes cutting power to the fuel pump.

 

[99_2door]

new development on mine..............truck was at the dealer for two days. they say the passlock sensor is actually fine but the ignition module (i think thats what they said?) is throwing codes and it needs to be replaced. they quoted $280 just for parts!!! damn it. i really need to find a way to bypass all this BS and just run an aftermarket theft system.

 

[MetalStorm]

yeah that would be ideal, but i think there are about 5 or 6 different modules in out trucks that all communicate with the PCM. So I'm not sure what effect, if any, that would have if you bypass it.