Gen1 Prius Lost all Keys - dealer quoted over $1500. Don't let this happen to you!

I had a Gen1 customer this week that lost their only key. Their dealer quoted them over $1500 to make the car drive again. Luckily I had a spare Gen1 immobilzer ECU with matched chip key and was able to fix their car for a fraction of the cost, even with the $150 tow to my shop.

If you have a Gen1 with only 1 key, MAKE A DUPLICATE ASAP!

If you lose your last key YOU ARE HOSED. Gen1's are a major PITA to make drive again (immobilzer ECU which is buried under dash has to be removed and reflashed or replaced with a good one with matching key)

If you have a master key (black head) you can buy the chip key blank (Toyota type 4C) on ebay for under $10 and program yourself without any tools via the chicken dance (just "cut" the key at a hardware store first).

If you have only one valet key (gray head) your best option is to have an auto locksmith or decent hardware store sell you a CLONE key ($40-$70)

Gen2 and Gen3 can be reset via software, much easier if you lose your last key but still expensive.

 

Gen2 and newer can be "reset" via Techstream with a seed code if you lose all keys.
No need to replace any hardware in the car....I've done it many times.

Gen1 requires immobilzer ECU to be physically removed and replaced with new, reflashed, or USED unit with with mated key. I often have used Gen1 immobilzers with mated keys, contact me via private conversation if you need to buy a set.

 

Jenrommel, Print this out and take it to the most senior tech at the dealer. You do not need a new ECU. You may need a more experienced technician. Normally the tech can do a smart key reset by using a Passcode derived from a Seedcode in Techstream. Did they try that ? (dealer will require locksmith credentials). If they tried a valid passcode and car is still "bricked" the procedure is a little more tricky but a savvy tech should be able to do it with access to another similar gen3 car. If the dealer says you need to buy a new ECU ask them to call their dealer tech support hotline and speak to someone smarter than them, or find a better dealer. Too bad the car is not in Colorado, you could tow it to my shop.

Here's what I recently did in a similar situation with a "bricked" Gen3. (power button was pressed more than 10 times after seed reset before a key was registered to car).

While researching smart key stuff I found the smart key course T9738 on TIS under Technical Training / Course Books. (BTW lots of good info on Toyota Smartkey systems there) Anyway, in Chapter 6 Parts Replacement there was a clue at the bottom of page 70 (page 4 in chapter 6 PDF) regarding “bricked” ECUs"

"Caution; After replacing the Certification ECU, do not apply power to the system (Ignition ON) more than 10 times before completing the New Key ID Registration procedure. Otherwise, the Certification ECU locks up and stops communicating. Service Tip; It is possible to salvage the Certification ECU if it stops communicating. Connect the Techstream to a like vehicle, access the key registration utility then move the Techstream to the faulty vehicle and attempt to complete the registration. This process is not guaranteed to work. “

I’m not sure if I could recreate my success, or if this is the best procedure but here's what I did to get the car to start up;

I borrowed a same year/model Prius, did a smart key RESET (using passcode) on the healthy Prius. Before add/register Fobs to healthy Prius I moved Techstream to sick Prius and chose SmartKey Registration. I then chose the 2nd option from the bottom “I am registering keys and have replaced the Smart ECU" (even though I didn't replace hardware) and was able to communicate to car and register Fobs.

I then took Techstream back to healthy Prius and Registered it’s fobs. (since I had reset healthy Prius all fobs would have to be re-registered to bring that car back to normal).

Both cars are functioning properly now.

 

If you register new FOB to a Gen3 after the passcode seed reset but before pressing power button 10 times it is no problem.

If you press the power button 10 times before registration of Fob that is what complicates things. AFAIK the "10 press limit" only affects Gen3 and newer smart key systems. I don't think you can brick a Gen2 in this fashion.

 

For Gen3 you can buy new fobs on Ebay or "virginized" or "reset" used fobs. They can then be programmed yourself with Mini-VCI or Techstream. If fob is new or virginized you do not need seedcode/passcode to add to your car. If you only have one fob left, get a 2nd ASAP so you aren't put in the position of JenRommel.

Door key is a little trickier, you need to find someone who cut do a side cut aka "laser cut" key.