Key Problem-key turns but engine won't start

[anndy]

Hello all, I'm looking for insight and advice regarding recent problems with our 2009 Matrix (it has around 65,000 miles on it with factory installed alarm system). All has gone very well with the car up until Friday night when the car suddenly wouldn't start. The starter was working but the engine was not turning on. The Service Technician at Toyota told us that the chip in our key appeared to be broken, so we brought our other key in to try it out, and that key also did not work either. It had the same problem. The Service Technician called back a few hours later saying the diagnostic tests still showed that the chip in the key was the problem. To replace one key it will cost $470. I've scoured the internet and have had difficult time finding anyone with a similar problem. Please help with any insight or advice you have! Thank you in advance!

[fishexpo101]

That's the first time I've heard of a chipped key going bad. It is easy enough for them to test it - just stick the key in a special transponder programmer and see if it communicates to the host.

Sounds more like the receiver/coil in the car is the problem. Though to test it, they need a known good key transponder or a spectrum analyzer. I'd see if they tech will verify the operation of the receiver in the car with a freshly programmed key - instead of just scanning via the OBD port.

I'm assuming they checked the battery in the key(s)? They are supposed to last a couple of years, but keeping the key in extreme weather conditions, moisture, etc. can kill the battery quickly. I believe the transponder is primarily powered by a coil near the ignition switch, though they use the battery as a backup. If the coil is not getting power to the transponder as it could be too many keys on the key ring, key ring garnish/charm that is blocking the RF getting to/from the transponder, etc. This is also the reason why some remote start systems don't work - no transponder to allow the engine to fire.

One site suggested using one key to start the car while using the other to move around and see if you can find a sweet spot on the coil (basically moving the other key around the ignition switch, steering column and see if it will start). Not 100% sure this will work, but something you can try pretty easily/quickly.