Won't Start

I have an '01 Sierra, SLT, Z71 with a 5.3L. I bought the truck used and it didn't come with the remote lock transmitter (key fob). I went to the local GMC dealer & paid $140, to have them get the codes for the proper fob & then set it up. After about a week of use the security light would come on while driving. I would just pull over & cycle the key and the light would go out. Then it started happening more often. Last week we had some cold weather & after work I went out to start my truck & it wouldn't. I thought it might have been froze up, so we towed it inside to thaw. The next day I went in and cranked it over & it started, but then quit. I unhooked one of the electrical plugs on top of the tank to check for power, and I had my friend crank it over, the pump ran. Plugged it back in & started the truck and it ran. Now if it doesn't start I unplug that connector & plug it back in and it runs...... Any help on this would help..... Thanks.... CheckEngine

I have an '01 Sierra, SLT, Z71 with a 5.3L. I bought the truck used and it didn't come with the remote lock transmitter (key fob). I went to the local GMC dealer & paid $140, to have them get the codes for the proper fob & then set it up. After about a week of use the security light would come on while driving. I would just pull over & cycle the key and the light would go out. Then it started happening more often. Last week we had some cold weather & after work I went out to start my truck & it wouldn't. I thought it might have been froze up, so we towed it inside to thaw. The next day I went in and cranked it over & it started, but then quit. I unhooked one of the electrical plugs on top of the tank to check for power, and I had my friend crank it over, the pump ran. Plugged it back in & started the truck and it ran. Now if it doesn't start I unplug that connector & plug it back in and it runs...... Any help on this would help..... Thanks.... CheckEngine

sounds like the ignition passkey system is going bad. sounds like a trip to the dealer to have it checked.

Check-engine:

I had a very similar problem, so let me put it out there for you.
I have a 2001 GMC Sierra and I purchased the OEM Keyless parts after the fact and installed the receiver myself. During the process I evidently blew a fuse by getting a screw driver in the wrong place at the wrong time, but didn't realize it at the time.
Not knowing that I had blown the fuse I went to start the car and the "Security" thing came up in the display area. The car would crank, start and die right away. I went into the internet to see how to deactivate or re-set the security warning (and get the truck to start), but nothing worked.
I then finally went looking at the fuses and found one blown. I replaced it and everything was fine.
I don't have the truck here at work, but I do remember it was one under the hood in the large fuse box on the driver-side fender side. I seem to remember it was a low amp. fuse on the lower right side, looking in from the fender.
Perhaps something in your new keyless install has popped the same fuse?
Good luck :)
>>Skip

Thanks for the info guys.. I had previously checked all the fuses & they were all good. The connector that I have to unplug in order to start the truck, I believe is for the tank pressure sensor. I don't understand why this would keep the fuel pump from running??? It is the plug further towards the back of the truck. When the key is cycled the pump doesn't run, unhook the sensor & cycle the key & the pump runs & the truck starts?????? Gotta love it....

Thanks for the info guys.. I had previously checked all the fuses & they were all good. The connector that I have to unplug in order to start the truck, I believe is for the tank pressure sensor. I don't understand why this would keep the fuel pump from running??? It is the plug further towards the back of the truck. When the key is cycled the pump doesn't run, unhook the sensor & cycle the key & the pump runs & the truck starts?????? Gotta love it....

Sorry it's been so long, before letting you all know what was wrong. I finally got the time to work on the truck last winter & found that there was a loose spade terminal in the fuel pump (elec) connector. These trucks have trouble with fuel pump failure early on & believe mine was replaced, but when they were checking for power, they spread the connector & made loose, so it was loosing contact ever once in a while... thanks again... CheckEngine