Thanks to searching this forum, I have learned to check a few things on my recently purchased LQ9 swapped Coupe.

I was able to pull codes in the dic today, as I was having a no crank issue. Sure enough, I got the 2723 code. This was actually the third time it happened to me. First time, I had the neg battery cable disconnected, went to start the car and dash lights on but nothing else, no crank. From experience with my old '96, I figured it was vats. Unhooked the battery completly overnight, and it started right up next day. Drove it about a half dozen times, no issue. Then the other day, I was going to drive it to work, and vats again. Today, same thing, but I cleaned the key with electical cleaner and she fired right up. Drove it a bit, but as has been the case, the security light was on. Got it home and started a few more times to check.

My question is this. Every video I've seen, everything I've read, shows people taking the whole dash apart to do the bypass. Is it not possible, maybe even better to just put the resistors on the white/black and purple wire at the BCM? I metered the key and it showed 7.49

On a side note, and other issue list. I have a battery drain issue. There is a usb port thingy in the cigarette lighter, and the courtesy lights in the hatch stay on. (I beleive there is an issue with the hatch latch/switch. Pulled those fuses and it's better. The alternator is suspect, making noise and showing charging system fault. For this reason, I disconnect the neg term on the battery when parked.

 

Yes, the easiest way to bypass the VATS is by soldering in the resistors at the BCM connector, you will have to fix the switch so the courtesy lights don't stay on, and you should remove and have the alternator tested.

 

Thank you. From everything I've seen, the process is to cut those wires and loop them with the resistor(s) in the middle.

I've got the new alternator, just need to slap it on.

 

Any tuner using HP tuners or EFILIVE can easily by pass the VATS system with a single entry change
IF that is your problem
Do you have a spare key ? If so try it 1st- after years of use sometimes the key will not be recognized by the ECM because the key gets worn out --Also there is a "pill " in the base of the key that has an ohn resistor that also will read wrong after years of use

 

Not the ECM the BCM

 

I'm pretty certain it's the vats. Combined with the 2723 bcm code when I pulled codes on the dic, and the fact that after spraying the key with some electric cleaner, it started. I figure I might as well just bypass it and be done with it. I'm not too worried about theft, being it's manual with big lopey cam that is very touchy to keep going from a stop. Very few people are going to get the damn thing out of the lot. Not to mentioned the sheer sound volume of the car, even if they keep going, they're going to attract more attention than they want. I'd give them 10 feet before they said "f-it". lol

 

I've got the new alternator, just need to slap it on. Unless you have found the correct replacement alt you will have problems with the charging system. It is recommended that you have your alt rebuilt. do not give yours up for the core
at the top of this page in the sticky threads you will find everything about the correct alt for your car

 

Well, it might be kind of difficult to discern what the 'correct' alternator is. According to the scan tool I have, I have the pcm from an '09 Yukon 6.2. The actual engine is a 6.0 iron block (lq9) bored out to 6.22 with 243 heads. Hard to say if the alternator I pulled was the original, I mean, the car is 24 years old and doesn't appear to have been a 'garage queen'. However, with the new one, i'm holding a steady 14 volts running, whereas the old one was right at or just below 13 volts. Though, I think I may need to up to a 145 amp at some point.

 

With the new alternator in, I left it parked for a couple of days. Up until this point, a couple of days of sitting would've drained the battery enough to not start the car. It started right up this morning.

 

You can do it at the BCM. Also, you can pop out the resistor from the key and solder it in line to eliminate the chip key. Good luck.

 

So, just using the resistor in the key. That's an interesting idea.

 

If you've disabled VATS through HP Tuner and have a push button start (race car), does this mean you can simply join the two wires and never need the key again?