Transponder key, revisited.

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aedgington

aedgington

Joined
Aug 30, 2005
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Location
Houston, TX
After having to go through the whole reflash bit again, I thought of something;

On Honda Accords, the stereo head unit requires an unlock code (CODE) if the battery is disconnected (some hare-brained theft detterent idea). If you put in the wrong code multiple times, the head unit locks itself (ERRE) and you supposedly need to take it to a dealer to unlock it.

However, if you disco the battery for a couple of hours, the head units flash memory loses it's charge and you're back to square one; put in the code and you're good to go.

So if anyone is going through the master key reflash situation, I'd like to request you unplug your ECU (overnight, maybe) and see if that's equivalent to a reflash; whereas the first key then put in is considered a master. If the ECU is holding the transponder frequencies in flash memory, then this is very likely to work.

Just a thought.
 
I'll try it...

Should I unplug the battery overnight or the ECU? If it's the ECU where it is at to unplug the damn thing?? :frown: OH, and yes I know where the damn battery is!!! :beer:

Let me know. I was the one with the Mystery Key problem posted a couple days ago, the dealer still hasn't told me if they will cover a new ECU.. :mad:

Fish
 
Excellent! I would suggest having a new key shell in hand (you still have your old guts), as well as the master key programming instructions.

If you have a lot of data in your nav system, then unplug the ECU. If you don't have a lot of stuff in your nav, just do the battery.

FYI, the ECU is behind the glove box.

Unplugging the ECU
- Disconnect battery ground.
- Remove glove box (2 plastic stop pins in the box, 2 hinge screws)
- Remove black plastic ECU cover behind glove box (3 screws, light switch connector, 1 rectangular plastic rectangle w/yellow wire mounted on it that can be left hanging.
- Unplug 4 connectors on left side of ECU.
 
ok...

So, how long would I need it disconnected? I have nill in my Nav so I'm going with the battery option.

You say to have a shell and programing instructions on hand, that kinda scares me... why would I need to program the key? I have no idea how to do it either, nor do I have the instructions.. However, wouldn't this be just as if the car sat with a dead battery for a day or more? I can't think that Toyota would make a customer go through reporgraming a key after a car sat with a dead battery... or maybe I am getting the idea of "programing" wrong...?

Anyway, let me know and I might be able to try it today.

Fish
 
I would leave it disconnected for 2-3 hours.

The reason you need the programming instructions, is that basically, when you have the ECU reflashed (wiped clean), the first key programmed is considered a master. I assume this would be your new replacement shell/blade or valet key.

Instructions:
1. Simultaneously depress and release brake and accelerator pedals 1 time.
2. Insert existing master key into ignition. Do not turn the key from the OFF (LOCK) position.
3. Within 15 seconds of inserting the key, depress and release the accelerator pedal five times.
4. Within 20 seconds of completing the above step, depress and release the brake pedal six times and
remove the key.
5. Within 10 seconds, insert the new key into the ignition.
6. Within 10 seconds, depress and release the accelerator pedal one time.
7. After 80 seconds the new key is registered and the security light will go off.
8. Remove new key and depress and release the brake pedal 1 time.


Try doing this set of directions and see if that makes either of your keys a master.
 
alright, here it goes

I'll check back in a few hours...

Fish
 
battery unplugged...

...at 10:08AM PST....

Off to the Pacific Science Center with the wife kids in the Volvo XC-90...

Fish
 
question for clarification

aedgington... so I only have one "master" key (with remote) and as my mystery key thread states I am having issues with it being used to reprogram another key into a master.. However, I do NOT have that other key right now, it's at the dealer, I just have my one so-called "master" that isn't behaving really like a true "master."

SO, do I just do steps 1-4 the stop since I don't have a second master key to insert for steps 5-8? Or, do I do steps 5-8 with the SAME key that I use for steps 1-4?



Thanks,
Fish
 
didn't work

Tried it twice to make sure I followed all 8 steps correctly. Each time the battery was disconnected for 4+ hours... no luck. I did all 8 steps with the same Key, but security light is still going... flash, flash, short pause, flash, flash LONG pause

oh well, we tried...

Fish
 
Sorry I was AWOL. Damn, that sucks. I really was hoping that would work. Oh well. Thanks for trying though, I guess we don't get an easy fix to the ECU hassles...
 
I have been reading all these treads as I just bought a 98. I also just have the regular key. But instead of the transponder key, I would rather have a key fob keyless entry. Is this possible?

Like this
c096_1.webp
 
I was reading the Lexus TSIB recently regarding the Immobilizer Key Reset (I see there is one for LC also in the TSB thread). It describes how the dealer with a programming tool coupled to Toyota Info Services can reset your key without replacing the ECU. It creates one master key (and cancels all other keys for your VIN) from which you can program/reprogram other masters and/or valet keys.

You might check with your dealer about using the Immobilizer Key Reset TSB and save the hassle of an ECU change.
 
Probably not, but compare FCC IDs on the back, maybe they have the same frequency...
 
Just check this out..on the page 6 toyota&lexus

http://www.hillmangroup.com/misc/Transponder Key Program.pdf


I did the "delete all the keys but one key from the unit" part. It worked. I mean security light started flashing after few seconds.So I removed the key (my master)and insert back again and truck started without any problems.

But I tried the second part "add a duplicate key" to add a second used ebay key but did not work:confused: :confused: :confused: Damn security light keep flashing:mad:

aedgington said:
Probably not, but compare FCC IDs on the back, maybe they have the same frequency...
Click to expand...
 
I've never had any success w/ adding keys either.
 
just got new remote key. was going to hardware store to get it cut, and thought id program it myslef. you guys havent had any luck with adding a new key? im kind of nervous only having one key for it...
 
I had success adding a new key on a 2000. It was a master, but not a remote master.

I simply got it cut and followed the instructions that they mailed with the key.
 
adding another master

KathmanduCruiser said:
I had success adding a new key on a 2000. It was a master, but not a remote master.

I simply got it cut and followed the instructions that they mailed with the key.
Click to expand...

so, what were the instructions??
 
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