05 yukon slt no crank no attempt to start.

[Tahoeyukondenali]

My 05 Yukon SLT makes no attempt to start after it sat in the garage all winter with the transfer out of it. When it was parked the steering column was tore apart because lost keys and I pulled the key cylinder and drove it in the shop by turning the dial on the ignition switch. Now truck is mostly back together except the key cylinder but but it won't crank over. So here's the million dollar question....... Does the 05 have a transponder key? Some site's say yes some say no.......what's the real answer?

 

[Doubeleive]

My 05 Yukon SLT makes no attempt to start after it sat in the garage all winter with the transfer out of it. When it was parked the steering column was tore apart because lost keys and I pulled the key cylinder and drove it in the shop by turning the dial on the ignition switch. Now truck is mostly back together except the key cylinder but but it won't crank over. So here's the million dollar question....... Does the 05 have a transponder key? Some site's say yes some say no.......what's the real answer?

no, if it did the key would have a "+" symbol stamped in the metal on the side near the outer plastic part.
define crank over? that could mean a lot of things
like starter does not engage?
starter engages but engine will not run or stay running etc?

 

[Tahoeyukondenali]

no, if it did the key would have a "+" symbol stamped in the metal on the side near the outer plastic part.
define crank over? that could mean a lot of things
like starter does not engage?
starter engages but engine will not run or stay running etc?

Gets power just won't even crank over crossed the starter with a screwdriver and the starter is getting power and is fine. It don't make sense i was able to start it with the ignition switch by turning the dial manually with column apart when I limped it in to the shop last winter to do the transfer case. Now the security light is on and it wont start

 

[B-train]

Did you power down the electrical system to do the repairs? If not, it's possible you got a phantom fault that needs to be cleared. Providing the ignitor cylinder is installed correctly. Where did you get a new cylinder? GM? I was under the impression that new ignition cylinders were becoming a thing of the past and can only be rebuilt by OEM to prevent theft. I don't know exactly what year that started, just that I have learned of that through people in the biz.

You could try the following:

1) disconnect the battery negative first, then positive. Once both cables are isolated from power and there is no power going to the truck, hold them together for about 10 seconds. Then, reconnect positive first, negative last. Key out of ignition. The purpose of this is to drain the capacitors of all the modules after 12v is removed. This is a sort of hard reset you can do and see if the BCM will acknowledge the key.
2) if you have a new cylinder, make sure the key that came with it is what you are using. The truck does know what key is being used and will lock you out if it doesn't recognize it. You can either put the key in and leave it in accessory mode for 30 min and see if the BCM accepts it. There is a power on/off cycle to train the computers, but I forget exactly what it is. Something like key on for 30 sec, off for 30 sec, on again for 30 min, then off, then attempt to start. I had to do something similar to that when I got a new PCM for my 05 duramax so the PCM and BCM would talk to each other. It's a factory imposed theft block. I'd Google PCM/BCM replacement for key learning.

Sorry for the long explanation, hope it helps

 

[Doubeleive]

Gets power just won't even crank over crossed the starter with a screwdriver and the starter is getting power and is fine. It don't make sense i was able to start it with the ignition switch by turning the dial manually with column apart when I limped it in to the shop last winter to do the transfer case. Now the security light is on and it wont start

if the security light is on then you need to do the relearn, depending on the year you can try the 10 minute relearn. insert the key and turn it to run, leave it on run for approx 10-11 minutes, until the security light stops blinking or goes out, then turn the key off for 1 minute and it should start. If not then you will need to do the 30 minute which is the 10 minute X3 without trying to start it until after the 3rd 10 minute wait. insert key turn to run for 10 minutes, turn key to off, then back to run for 10 min, turn key to run repeat for 3 cycles.

 

[Snowbound]

Sounds to me like there is no key and just turning cylinder. If I’m reading this correctly, get yourself a new ignition tumbler with key and try again. But I believe you will have to do relearn as described above.

 

[Doubeleive]

to clarify a relearn needs to be done when a new ignition cylinder is installed not because of a transponder key it is because there is a magnetic sensor on the ignition cylinder and inside the housing called a "hall sensor" that needs to be learned by the security module up under the dash. Instead of having a transponder on the key it is integrated to the cylinder instead, in 07 they changed it to a transponder key and the security module is a electronic ring around the outside of the ignition cylinder behind the steering wheel plastic shroud.

 

[rockola1971]

Did you power down the electrical system to do the repairs? If not, it's possible you got a phantom fault that needs to be cleared. Providing the ignitor cylinder is installed correctly. Where did you get a new cylinder? GM? I was under the impression that new ignition cylinders were becoming a thing of the past and can only be rebuilt by OEM to prevent theft. I don't know exactly what year that started, just that I have learned of that through people in the biz.

You could try the following:

1) disconnect the battery negative first, then positive. Once both cables are isolated from power and there is no power going to the truck, hold them together for about 10 seconds. Then, reconnect positive first, negative last. Key out of ignition. The purpose of this is to drain the capacitors of all the modules after 12v is removed. This is a sort of hard reset you can do and see if the BCM will acknowledge the key.
2) if you have a new cylinder, make sure the key that came with it is what you are using. The truck does know what key is being used and will lock you out if it doesn't recognize it. You can either put the key in and leave it in accessory mode for 30 min and see if the BCM accepts it. There is a power on/off cycle to train the computers, but I forget exactly what it is. Something like key on for 30 sec, off for 30 sec, on again for 30 min, then off, then attempt to start. I had to do something similar to that when I got a new PCM for my 05 duramax so the PCM and BCM would talk to each other. It's a factory imposed theft block. I'd Google PCM/BCM replacement for key learning.

Sorry for the long explanation, hope it helps

Wrong. The Passlock system does NOT know anything about the key inserted into an ignition lock cylinder. It is ONLY checking to make sure a key is in the ignition lock cylinder. This prevents the old school way of stick a T handle into the igniton lock, breaking the lock by cranking the T handle forward to steal a vehicle. This type of theft will not be allowed by the Passlock system.
The Passlock system has a simple magnetic sensor that senses the key in position when the vehicle is started and then the components of the system send a signal to the BCM and if the BCM approves of the everything being good to go then the BCM sends a pass/fail signal to the PCM.

If PASSLOCK determines that there is no key but the vehicle was attempted to be started it will allow the engine to start and run for a few seconds then shuts it all down.

GM hasnt used the old "chip"(resistor) on a key security system for decades. My 1985 Corvette has it. None our generation and prior K chassis have the transponder key anti theft system either.

The important takeaway for the PASSLOCK system and troubleshooting engine running, starting, cranking problems is that the PASSLOCK system does NOT prevent the engine from cranking or starting. It lets the engine run for a few seconds then it immediatley dies.