Used Prius only came with Valet key. Big deal?

[fthorn]

Originally Posted by Patrick Wong

Using the master key, it is possible to lock the trunk so that the floor-mounted lever does not function.

Oh, good to know. I'm assuming that is a fully/only-mechanical limitation, and has no electronic ties?

If so, then they could just cut me a new mechanical (non-transponder) key, I would assume.

[RobH]

Originally Posted by fthorn

Oh, good to know. I'm assuming that is a fully/only-mechanical limitation, and has no electronic ties?

Right. The trunk/doors do not use the transponder, only the cut of the key.

One thing you could do is to have the trunk lock changed to accept the valet key that you have. If you can remove the trunk lock cylinder without using the key, then you could probably even do it yourself. Or take the cylinder and your valet key to a locksmith.

[w4y]

Originally Posted by Patrick Wong

I've attached a couple of TSBs that relate to this subject. The bottom line is that if only a valet key is available, it is not possible to program the immobilizer ECU to recognize additional keys. It is required to replace the immobilizer ECU in order to accept new keys.

Regarding your effort to think outside the box, it is not practical to remove the immobilizer ECU functionality from the vehicle - unless you are familiar with digital circuits, take the time to understand the signals that the immobilizer ECU is providing to the hybrid vehicle ECU and the body ECU - then develop a black box that pretends to be the immobilizer ECU and allows the hybrid vehicle ECU to start the car.

Most of this information is correct.

It *IS* possible to reprogram the Immobilizer ECU, but I believe it is a black market procedure. Somehow, the ECU software was leaked from Toyota and *A FEW* locksmiths who specialize in this stuff will be able to reprogram the Immobilizer. I had to get this procedure done on my car. It's not cheap, but far cheaper than replacing the ECU completely (to the tune of $1500, according to a quote from a Toyota dealer).

I was given only 1 key (master) with my 2002 Prius, and I lost it. I called various local locksmiths, and finally found one that could reflash the ECU. It was a 3 hour job and requires 2 people to finish it in a timely fashion, because the ECU unit is located deep inside the dashboard.

The best hope you have at this point is hope you never lose your key. If you do, you have no choice but to reflash the ECU or replace it. If you can get a master key cloned from the valet and it's cheaper than reflashing, I would say you should go ahead and get that done, because reflashing the ECU cost me about $500.

[Patrick Wong]

Doug Schaefer offered me a suggestion which fits the category of thinking "outside the box":

Cut off the transponder head on the existing valet key. Attach that head behind the dashboard so that it is hidden from view, and in range of the immobilizer ECU antenna. Now the immobilizer ECU should be happy.

Have a few mechanical keys made up, using the pattern from the valet key. Each of those mechanical keys should be able to start the Prius, since the transponder head has been attached to the inside of the dashboard in range of the immobilizer ECU.

[fthorn]

Originally Posted by Patrick Wong

Doug Schaefer offered me a suggestion which fits the category of thinking "outside the box":

Cut off the transponder head on the existing valet key. Attach that head behind the dashboard so that it is hidden from view, and in range of the immobilizer ECU antenna. Now the immobilizer ECU should be happy.

Have a few mechanical keys made up, using the pattern from the valet key. Each of those mechanical keys should be able to start the Prius, since the transponder head has been attached to the inside of the dashboard in range of the immobilizer ECU.

Most excellent brainstorming!

[RobH]

No need to damage the original key. Just attach it intact near the ignition switch.

First you should get several non-transponder duplicate keys (about $2 each) at the local hardware store. Then try to start the car with the duplicate and the original transponder key near the lock. You need to find the range of the transponder. It's just a few inches, so you'll need to attach the key somewhere within range.

If there's no practical way to attach the key, you may want to consider an immobilizer bypass unit. You put a transponder key inside the bypass box, and run a wire from it to the antenna around the ignition lock. When power is applied to the bypass box, it relays signals between the box and the ignition lock antenna. The wire is generally easier to locate than the full size key.

There are also immobilizer bypass units that can learn your transponder code. They don't need the key once they've been set up. I don't know if there is a learning bypass box available for a Prius or not.

I do have a bypass box on my 2006 with a transponder from a keyfob in it. Some day it's going to be a remote start system, but for now it is just a spare key.

[fthorn]

duc(k/t) tape, I'm sure. solves all engineering conundrums.

[w4y]

Doesn't that defeat the whole purpose of the immobilizer in the first place? Your car will be considerably less secure.

[dgoldst]

The people here in New Mexico steal cars by loading them in or on a trailer. So much for the smart keys. Good idea for taping the key to the steering column. My Toyota stealer wanted 600.00 minimum to replace the key ecu and cut the new masters.

[fthorn]

Originally Posted by w4y

Doesn't that defeat the whole purpose of the immobilizer in the first place? Your car will be considerably less secure.

They sell insurance here.
And I don't really feel the threat of theft is high.
I've never had anything stolen, vandalized, etc.