fatspider

Hey guys,

So I have been having this problem for nearly 4 months now. I don't drive very often.
I left my 2006 IS250 in a garage for a 3 months after it got towed (long story- but it was cheaper for me to pay towing fees there than pay parking fees in the garage).
I emptied the tank as much as possible before storing and had a can full of seaform in the tank as well.

Unfortunately when I came to pick it up, the key would not work at all. Both sets were not recognized and I could not get it started at all. I could only open the door manually.
I had it towed to the Lexus dealership where they could not find what was wrong either and instead had to re-flash the entire ECU (charging me 2 hours of labor at $370).

After they did that, it worked fine for about 3 days. I left the car again for about 1 week and when I came back, it would not recognize my key AGAIN.

Below are things I've tried already:

• Hold key near starter button while pushing
• Replace all batteries in the key fobs
• Disconnect negative terminal on battery for 20+ mins

I don't think the car battery is the issue as lights turn on when I enter the car and headlights/taillights work fine.
Has anyone ever dealt with this before?!

The dealership said something interesting when I brought the car in as well, that the ECU had been flashed already and that had to have been a deliberate thing.
Also, there were a few things missing from my car when I picked it up from the tow yard so I know for a fact that someone had been in it (possibly setting off the alarm).

Please does anyone have ANY ideas as to what could be happening? I'm at my wits end and have browsed nearly every thread on here discussing the issue.

2013FSport

iTrader: (2)

That's a tough one and not normal. What history do you have that would explain the reflash? Are you the original owner? Have you had keys replaced?
By reflash I don't mean just adding a key! An 06 could have had some update performed.

So does this vehicle drain the battery in say a month? Will it start after 3 weeks of sitting?

As for the fuel, leaving it completely full is best especially for just 3 months.

fatspider

Thanks for the reply. I'm not the original owner but have owned it for the past 5 years and never once had this problem. It only started after it was towed to the yard. I have the original keys (both sets).
It started fine after sitting when I would come by to drive it a bit (after sitting 3-4 weeks).
Also, the lights and headlights work when I get in the car, just the system wont recognize my keys to let me start the car.

The reflash, as explained to me by the Lexus dealership, was apparently the only way to get the car started and actually recognize the key. They said that when it came in, the system was not recognizing my key AT ALL and that it's likely someone deliberately reset the system to begin with. Does that sound accurate? I wonder if the tow yard set off the alarm and then reset the ECU themselves..

andrewwake

iTrader: (1)

I wonder if the tow yard jumped pins to bypass the alarm and left whatever they used to bypass in place or shorted something? This is just a guess though.

MikeFig82

iTrader: (13)

Any thoughts on the push start switch?
it has amplifier written on it.

fatspider

Do you think a defective start switch would be detected at the dealership?
They reset the ECU and it was working for about a week...I'm assuming that they checked the fuses and etc.

2013FSport

iTrader: (2)

That would imply two to three faults. But I may be mistaken here?
The BCM knows the keys RF ID and the courtesy light door function as intended. It is my understanding that the ECM must accept the key for this to happen.
Taking this a step further one has to wonder how the main ECM does not accept the key for the start sequence?

That said for key and associated switch to work from close proximity, they use a different principle such that a dead fob won't leave you stranded. A hall sensor and chip ID like a standard ignition switch before push button start come into play. So one has to ask what is the interpreter between these two systems is how is it only working partially? Or did tampering cause all of this?

Did the tech tell you how many keys were registered to that ECM? That may be moot point if they unregistered the previous keys. But again the BCM knows those keys. Why? Once the keys are registered, it's stored in ROM and should not go away if the battery goes dead or you leave the car sit. Makes me think the ECM is defective. And if not mistaken, yours would not be the first.

fatspider

There are only 2 keys registered, I have both of the originals.

The keys definitely don't work on the doors. It won't use the proximity sensor nor with the unlock/lock buttons work. I need to use the key manually to open the doors.

I'm not quite sure I understand what you're getting at though. Is this something only the dealership could fix?

MikeFig82

iTrader: (13)

Any chance the key FOB batteries are installed backwards?
Also get your battery load tested at a local Auto parts store.
These cars do strange things when having battery 12+V issues.

MikeFig82

iTrader: (13)

Ok digging around the Prius forums. A thread popped up and the info is worth looking into. The OP locked the doors manually leaving the FOB inside the car for a few hours. Came back later and the fob was working again.

POST #11

https://priuschat.com/threads/key-not-detected.146545/

fatspider

Yeah pretty sure the batteries are in correctly. There's a red light that flashes each time I press any button.
I guess I'll get my battery tested today. Thanks!

2013FSport

iTrader: (2)

Read that wrong. Thought you said the puddle lights came on. Wrong thread....
You might look into to buying techstream. You look yourself then. Its expensive.

fatspider

This is great! My car was left for a while away and my daughter definitely has been pushing the button. I am guessing it was unsynced. Will try leaving it in the car for a few hours.

2013FSport

iTrader: (2)

Read through the Prius thing and it reminded me of and incident I had. I had high output 12V to USB in the ashtray area. No big deal until you charge a phone AND throw your fob near that charger whereby car reports fob not detected.

My point is there could be a component failure producing RF noise (radio frequency) that kills the communication between the car and the remote. But again the chip ID should work when held to button.


I moved the charger to the center console and this has not been an issue since.

As for fob batteries; touching the cell leaving your acidic little paw prints on it leads to oxidation over time. From here the contacts loose contact. The battery measures good and a new one temporarily fixes the problem until the oxidation returns.

Moral of the story; don't leave greasy prints on battery. If it measures good, wipe it and the contacts with alcohol and reinstall. No time to clean properly; spin the cell to restore continuity.