Lacross Passkey III issues

[shamar20]

I have a 2007 Buick Lacrosse CXS, 56,000 miles. I was backing out of a parking space and a message came up, "traction off", then another "service security system". I started out of the parking lot and noticed i had not gauges of any kind. I drove home (10 miles), turned the car off. I had to leave again a few minutes later. The car wouldn't start, no sound, nothing. Four tries later it cranked and ran fine. I drove 45 miles, had it checked out by our mechanic, who found nothing wrong or unusual. It ran fine another 10 miles. I turned it off, went shopping. About 45 minutes later it did it again, no sound, no crank, nothing. I called our auto club who sent out a tow truck to try to jump start it. No good. He told me it might be the battery.

We had it towed to our mechanic. He said it looked like an electrical problem and suggested we take it to the GM dealership. We did. They called me three days later to tell me it needed a new ECM - $1200 - and he was unsure if that would fix it. Not having that kind of money we had it towed to our house. Eventually we found out we might be able to recode the passkey III and did that and it started. Lasted a few days and quit again. The battery was almost completely dead. We bought a new battery and I recoded it and it worked exactly one week and is now dead in the driveway again. I will not recode now. The only difference is that now the message says "traction off" and "service stability system". Anyone out there having a similar problem??
Any ideas, please. I am about ready to just get rid of it. Frustrated....
Thanks, Sharon.

[Rasp]

honestly you might want to try that ECM idea. But go to a wrecker and try a used one. Should be way cheaper than dealer.

Wish I could help more.

[Blue Bowtie]

Welcome Aboard!

I am not hinting that the problem is the same, but the attached thread might be a clue as to how the PK3 system can act with a failing RFID chip in the key:

http://www.automotiveforums.com/vbul....php?t=1148365

For very little cost I purchased new, pre-programmed blanks and had one cut at my local locksmith for 95¢ (regular key cut fee). Since you already know how to "teach" a new PK3 blank, it may be worth a try, and at the least you'll have a spare key. That solved my entire problem. I'm not exactly new at this, an d you can see how deeply involved I got in analysis before trying the "obvious" and easy solution.

Just be CERTAIN you get the correct PK3 or PK3+ blank.

[shamar20]

Thanks for your post. Where do i purchase pre-programmed key blanks?

[Blue Bowtie]

The link is in the previous post - Just click on "pre-programmed blanks" to view that.

[Tech II]

Well, for one, the keys are not pre programmed...

Second, don't you already have a spare key? If you do, just use that one to see if the problem re-occurs....

If it does, go to another GM dealership....they obviously didn't know what they were doing, if the car wouldn't start for them.....did they write ANY codes on the repair order? If no, then definitely go to another dealership.....

It sounds like you have a SECURITY problem, which should have set codes, which should have been listed on the RO......It could be the Security system itself, or it could be a bad connection in a harness somewhere(fretting condition)....

For a garage to tell you that it will cost you 1200 bucks on a guess, you should call GM Customer Assistance and let them know about this....

If I have a car in my bay, and it won't crank over because the starter enable relay is not getting a signal from the Security system, and I can't come up with a definite answer, than I should pack my tools up and go home....

Does your vehicle have remote start on the key fob? If it does, it won't start with the remote either? If it does have a remote start on the fob. and won't start, that eliminates the key, and the Passkey module....

You replaced the battery....do you have a charging problem, or draw?

I have found the PKIII system to be more or less foolproof......and can only think of a few instances where I have found problems...I have seen bad contacts in the starter enable relay(you can try swapping out that relay, with another relay in the fuse block, that has the same number).....I have seen a bad hood latch switch......I have seen the exciter ring move on the lock cylinder retainer, causing intermittent problems......and the main culprit I have seen is aftermarket security systems/remote starters, that are tied into the system.....easy fix is to remove them and repair the wiring....

That crank relay is grounded by the ECM, and if it does't get a ground from the ECM, it doesn't necessarily mean, it's the ECM.....the BCM gets it's signal from the key, via the Passkey module.......the BCM also needs a signal from the Ignition switch, that the key is in the crank position......the BCM then sends a request to the ECM, to ground the relay.....

That's why it is important, that ALL codes be written down on the RO.....for example, a code for the hood latch switch, will prevent a car starting.......various BCM or "B" codes(which can't be read with an ordinary code reader or cheap scan tool), would help in the diagnosis also.....

Not every garage has a top electrical/diagnostic guy, and if they do, sometimes they are not the guy working on your vehicle....it is up to you, to tell the Service Manager, in a case like this, you want his top diagnostic guy on the job.....that Dealership already had it's shot....I would try another.....even though you have a Buick, you can bring your vehicle to any GM shop, it doesn't have to be a Buick one....

[shamar20]

Thank you for responding. To answer your questions first, no codes written on the RO - i just looked. It says, "Found vehicle to not have any communication with multiple modules. Found ECM to possibly not be receiving fuel enable code from BCM due to a fault in ECM. Recommend new ECM as a starting point. May need more diag after repair". For which he charged me $250.

I do have two keys and tried my spare key the first time i successfully recoded the passkey III system. It worked and i drove the car for a week, making several trips, about 120 miles altogether, then one morning i went to start it and got the same issue. This was after replacing the battery.

I do not have a working keyless remote. i have two that have not been programmed, as the dealer wanted $60 to do that i just never got around to it.

So i tried a couple of things. I put the charger on the battery and charged it up fully, tried recoding it with the charger connected to not let the battery drain while i was cycling through the steps. Did not start after finishing.

I next recharged it again to make sure it was up to full charge, disconnected the battery, let it sit for a half hour, reconnected the battery and tried it again without the charger connected. Still no deal. This is where i am now, frustrated and thinking again about just aborting and getting rid of it. i lived on a fixed income and cannot afford to just keep replacing things and not knowing if it will ever be fixed for sure. i do have a mechanic about 60 miles from me that says he knows about these things and may be able to help, but now i will have to get the car towed there before we can even try.

[Blue Bowtie]

Tech - The replacement keys are obviously not "taught" to the vehicle but they do have a valid RFID string. If you place the blank into an ILCO or other reader/programmer it's obvious that the RFID has a valid value. If you try to over-write the string the new key will be dead.

I mentioned that the key would have to be learned by the VTS module so it can signal the PCM, but the OP apparently already went through that with the original key so it was assumed that it was not necessary to further detail the procedure. Since the PK3 and 3+ systems can learn/retain 10 different strings, there is usually no problem in doing this.

That said, it does sound as if there might be a CLII/GM-LAN bus issue, be it a connection or module - Including the instrument panel among all the other possibilities. And as you indicated, a reputable/capable repair organization should be able to determine that pretty quickly.