OP
OP
Phisher
Member
Battery was at 13.2 when I went in last night not it's at 10.4
No start issues again
- Thread starter Phisher
- Start date
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rockola1971
Full Access Member
So something is drawing your battery down. Charge battery up to 13.0v+ and pull your BCM fuse and check it again the next morning. See if battery is still charged to atleast 12.8v+. You may also want to charge battery up fully and take it to an autozone or equivalent and have the battery load tested to make sure the battery isnt bad since a bad battery will mimic something draining it down....which it is indeed being drained down internally by a high resistance cell causing all the havoc in a bad battery. The battery has to be fully charged before it can be load tested properly.
There are alot of possible causes that have been known to happen to cause a battery to be drained down.
Bad battery, bad ignition switch (electrical one), bad alternator, bad grounds (BCM), wires partially shorted to ground, bad OEM amplifiers (at speakers), shorted auto hvac fan module, bad door switches (lights), bad starter (Solenoid partially shorted across contacts) and much more possibilities.
Follow the steps and well will narrow it down to the cause and then verify the bad part(s). I use to work on F/A-18C Hornets and F-14 Tomcats (as an electrician). I can handle your Yukon!
If or when we have to get in depth, you can PM me and Ill give you my phone number and we can real time troubleshoot this Yukon over the phone to get things moving faster. Get that battery fully charged and tested.
OP
OP
Phisher
Member
I do have a friend down the street that has a code reader we're going to throw that on here later and hopefully it will tell me something but I'm hoping it's not the ignition switch again like I said I already put two grand into this lockout system to never have it happening and I was told but what I've read out there it can happen multiple times and at any time so I think all you again for all the help and rockola1971 i pmd you
MassHoe04
Full Access Member
We already determined that funds are extremely tight and you are in a pinch... But it has been to the shop once (at least) for the Passlock. Now, possibly mentioning another trip to the shop for fobs.
One of the Tech 2's built-in functions is programming fobs with the security system. If you could find the way to get one of these, you could program fobs all day long and not depend on a shop to do it for another couple hundred bucks.
When I had my no start this weekend, having the ability to look at the status of my ignition switch, live voltage readings and status of the park/neutral switch really helped me decide that the starter was my issue. And, it was. I was able to make that diagnosis as an educated guess, given all the information the Tech 2 was able to provide me.
Information is the key! The Tech 2 can provide so much information before you even disconnect any wires or put a wrench on anything.
I used to think: A real luxury. "Yeah. Tech 2... Good for you. Glad some of you got one. Nice, but expensive! Maybe someday, but I got other stuff to work on first."
I have used it twice and I have not had to bring it to a shop. I was able to diagnose myself and not have to rely on a shop to fix the issues.
Local shops charge about $100 a pop just for scan tool diagnostic fee. Add 1 hour minimums @ about $100/hr.... My Tech 2 is now officially paid for in the savings I realized. I am actually $100 ahead now!
All the things I thought were hype on having a Tech 2, are 100% legit. I didn't just drink the Tech 2 Kool-aid. My experience and what other people have found is true. Buy one, if you can find a way. Having this tool can make the world of difference.
Mechanics don't get stressed out when diagnosing problems. Because they have a Tech 2, or an Autel tablet scanner or Snap-On or something similar. The bi-directional scan tools dive into the systems so deep, you really can use the information to narrow down what parts are working and narrow things down to the part that is not doing what it should.
Sorry for the ramble, but just wanted to explain again, that the cost of a Tech 2 seems a bit much at first. But, it is a real game changer in being able to get the deep detailed information needed to figure things out.
If you can't buy a Tech 2 or make a friend with someone nearby, who has one... OK.
But, really... Our ability to help needs all the details you have. And be prepared for even more follow-up questions.
Diagnosing over forum posts is a lot like bringing your vehicle to an expert mechanic, but the mechanic is blind. You need to describe everything you see, hear, smell or know about the vehicle. Any detail, even if you think it is not important or related to the problem, could be helpful in diagnosing your problem. Something might pop up as an "ah-ha!" discovery and solution.
MassHoe04
Full Access Member
Very generous to offer a guy some 1-on-1 help @rockola1971
You represent the best of this forum and what it is all about!!
if it is still blinking after they replaced it then how did you drive it home? presuming they did what they said they did it should not have even started up if the light is blinking, if you are driving around and the light is blinking then they did not replace it and simply bypassed it or did something wrong.
and this if they worked on it and 2 weeks later it wont start and the security light is flashing then it should be on them, towing and all, they should have it towed in, not you.
maybe I am missing something here?
so from what I gather from a variety of post information is it will not start and security light may or may not be flashing?
so question?
by no start do you mean the starter turns but the engine will not run? (like it has no fuel, so it just spins?)
or is the starter not turning at all?
presuming it is spinning and you have confirmed it has fuel, then next up is spark
have you confirmed it has spark or no?
if it has spark and fuel then you really need some kind of tech tool to confirm it has correct air reading and timing.
check all fuses! every single one.
you mentioned the instrument cluster not showing things correctly? like low fuel, etc? this would lead me possibly to a bad ground, without going deep down that rabbit hole I would check the basic stuff around the battery and engine bay and body grounds under the front end and confirm the grounds are good
so question?
by no start do you mean the starter turns but the engine will not run? (like it has no fuel, so it just spins?)
or is the starter not turning at all?
presuming it is spinning and you have confirmed it has fuel, then next up is spark
have you confirmed it has spark or no?
if it has spark and fuel then you really need some kind of tech tool to confirm it has correct air reading and timing.
check all fuses! every single one.
you mentioned the instrument cluster not showing things correctly? like low fuel, etc? this would lead me possibly to a bad ground, without going deep down that rabbit hole I would check the basic stuff around the battery and engine bay and body grounds under the front end and confirm the grounds are good
OP
OP
Phisher
Member
All you guys represent the best of this forum I appreciate all that help you guys have been giving me here's another bonehead move of mine I didn't say that the stereo is not in this it's just the wires and they're all wrapped there was a aftermarket in here and the guy I bought it from took it out and was supposed to give it to me so I'm wondering if that's why it didn't die and have this issue two weeks after buying it and then the shop I took it to did the ignition and got me around the padlock but here we are a month later and it's happening again I'm starting to think this could be the culprit
radio has no say so over the security system, nor would it affect if the engine can start and run or not, at best it would be a crossed wire draining the battery while it is not running.
please answer the questions i asked to clarify the issue, we can't read your mind
Well since no start can mean a lot of things.....
key in dead i.e. dead battery
key in click click click i.e. low battery
key in, no starter response i.e. dead battery/bad starter/bad ignition
key in starter runs but engine wont run -at all i.e. no fuel/no spark/bad timing
key in starter runs, engine starts and dies i.e. fuel cutoff
i'm sure i'm missing some
OP
OP
Phisher
Member
Yeah but doesn't the OnStar system have to run through the stereo cuz as soon as I started hooking wires back up all of a sudden things on my dashboard started turning off and Gauges started working again..... And as of now it still doesn't start but all security lights have shut off the only thing that lights up on the dashboard now is the service engine light and the gauges work
OP
OP
Phisher
Member
The engine just cranks over and over and over I've replaced the fuel pump because I thought that was my issue then still get nothing just crank over instrument panel shows an empty tank even though it's a full tank and even the lighted up low fuel not only the gauge so I pulled the relay and jumped it by putting a wire from pin 30 to pin 87 the fuel pump works but I still get no start I have gas coming out at the engine but it just turns and turns. about a month ago a month and a half I couldn't start the vehicle at all had to have it towed to a shop and $2,000 later I had the passlock system reset and new ignition put in all that good stuff.. now as far as checking spark I've been told that that would have nothing to do with this that I have some sort of short or once again the passlock system or security system is screwing up and locking it out and it's just frustrating because I bought this vehicle the week after Christmas for about 4 grand then dumped another two grand in and now I'm about another thousand into with what I've done to it this week and it still doesn't run at this point I'm considering just taking it to a scrap yard I don't know what else to do but hopefully rockola1971 and I can converse here in the next week and maybe get it figured out cuz that man has been filling me full of knowledge
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Phisher
Member
It has blinked since the moment I put the key in the evening I took it home from the shop I just found out today too after calling them once again that the three wires in the ignition one of them was loose and they forgot to put it back in so maybe I should check that and sure enough I opened the neck of the steering column and the yellow wire isn't even in so obviously they bypassed something just to get it running now I'm at a loss but again once I started hooking the stereo back up and it's hard wired not just a harness I lost everything on the dashboard except the check engine light my gauges instead of saying no gas now shows over full so I don't know this is now my second or third vehicle in a row with electrical Gremlins my last was a classic bronco that I parked because the electrical issues that's it for 2 years until I finally sold it next was another Yukon that had major electrical issues and once we figured it out it was the grounds there were so many of them corroded that's the joy of living in Minnesota everything gets eaten away so here we are with another Yukon having the same nightmares I think I'm going back to just owning a bike
OP
OP
Phisher
Member
No start I mean I put the key in I turn the key and it just cranks over and over and over brand new fuel pump brand new fuel filter brand new fuel relay the fuel pump won't work with the relay in but if I jump it with just a wire from pin 30 to pin 87 the fuel pump engages I get fuel at the engine it sprays out of the overflow if I press the release but I still get nothing if I spray starting fluid in I get nothing it wants to turn over but it just will not that is what is my problem
if it was the security system it "should" start and then die within a second or two
here is some more information on how that works, the gmt 800 should be passlock I
GM PassKey and PassLock overview
Learn how the different versions of GM's Passlock and Passkey immobilizer system work to prevent theft and how to diagnose them
ricksfreeautorepairadvice.com
rockola1971
Full Access Member
I would disconnect the stereo since it is likely hooked up to something in the dash circuit that it is not suppose to be.
That yellow wire in your column is the Passlock signal wire going from your passlock hall effect switches to your BCM and it MUST BE hooked up for the system to allow the engine to continue to run. As another has said that the passlock system typically allows the vehicle to start up but then immediately shuts it down if the passlock system detects theft or is broken. The passlock system is integrated into the ignition lock cylinder assembly. On earlier models it was a separate module behind the IC. There are 10 possible passlock codes so when a ignition lock is replaced you have a 1 in 10 chance that you wont have to reprogram. Doesnt matter really since reprogramming is stupid easy to do. The tattletale that your vehicle has a broken passlock system or is in security mode active is your passlock light on the IC is blinking continuously.
To program:
Step 1
Insert your key in the starter, start you car as you usually would and let it stall. Keep the key in the "On" position. In other words, don't turn the key back to the "Off" position. You will know the key is in the "On" position because you can use the A/C, radio and see all the lights on the dashboard when it is in the "On" position.
Step 2
Wait until the "Theft Sys" light on your dashboard stays on without blinking. This will take approximately 10 to 15 minutes.
Start the car immediately once the "Theft Sys" light stays on steadily. Remember to not turn the key off. Your car will now reset the passlock system and start as usual.
How to Disable a GM Passkey System
Some GM vehicles come with a factory-installed anti-theft system commonly referred to as the passlock or passkey. Due to glitches with these built-in security systems, GM owners may experience problems trying to start their vehicles. When this happens, the security (theft sys) light randomly...
itstillruns.com
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Phisher
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I've done this passlock reset several times and it does nothing I can't get the security light to do anything it's either off which I just realized now that there was a blowing fuse for the radio so I replaced that now the light comes back on but it's off once I shut the door so I'm at the point I'm just selling this vehicle I think
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