I can't start my 2008 Prius without inserting the key into the slot, Help!

I had this happen on a 2005 (I was actually the rescuer), I couldn't understand how the fob could be locked in there. If you press the lock button on the door handle, the car won't lock. But if you use the lock button on the armrest, it'll allow you to lock.

I'll try it on my 2006 model in a bit, just to see if I can duplicate it.

 

FYI this works for me on an '05. Looks like a good way to test with a single fob.

Here's what I did, sequencing may be important?:
- open drivers door
- place key fob on center console
- power on to Ready (brake pedal depressed)
- roll down drivers window
- power off
- lock doors with driver's armrest button
- get out and close door
- car gives warning tone and unlocks doors

 

and that's due to the ignition sensor, and not the door sensor?

 

I believe so. The ignition sensor (center console) should be what tells it the key is inside, I don't think the door sensor knows the difference. My understanding is the door sensor's antenna pattern is heavily biased looking outward, so generally it shouldn't see it at all when the fob is in the middle of the car.

There is also another interior sensor in the back, which I'm not quite clear what it does. Probably to help keep you from locking your key in the trunk? Not sure if it also allows you to start though. Guess that's another one to test.

Rob

 

Room oscillator (in center console) is the one that lets you start the car without key in the slot. Others are only for other functions.

 

The programming of the fob may be corrupted. A "Chicken Dance" might work here. Search for "chicken dance" on PC.
Otherwise a $100 dealer checkout ensues, that makes a Mini VCI tester with a laptop (XP, Vista) a workable mode. I hope some one has used a Mini VCI to reset fobs, who can tell us how it is done.

 

This is weird as now I can't lock the key in the car, it unlocks as you've described. I know it was possible as I had to unlock the door with a second key to get the key out for my brother. He had the key in the front cupholder, maybe that's a void area. Oh well....

 

FYI, I did try starting the '05 with the keys in the trunk and no go until they were right up against the back seat (presumably where the center console sensor could "see" them). So it would seem that the rear interior sensor is only for key detection, not starting. I also popped the covers off and looked at both, and they are different part numbers. Was hoping you might be able to swap them to test.

You can access the center console sensor by popping off the rear cup holder. It might be worth having a look and making sure its hooked up. Maybe even try unplugging the connector and re-seating even if it appears to be connected.

 

Ok, interesting. I'm not sure that's conclusive, but it would seem to point to the inside sensors working. Its still possible that the rear inside sensor could be seeing the key and causing the unlock. If you wanted to narrow it down more, you might try unplugging the rear sensor and seeing if it still works as expected. Or you could unplug the front sensor to see if it stops working.

If that still seems to indicate the sensors are working as expected re: locking behavior, then the issue might be with the security ecu?

Rob

 

it's a big job, everything packed away, don't you know. have you tried the 12v reset disconnect trick?

 

Both inside sensors are pretty easy to get at. The center console one is hidden behind the rear cup holder. Lower the cup holder, apply pressure to the far end and you should be able to get the whole back of the console to pop free. The sensor is a little white box attached right to the back of the console. To put the rear console cover back on, close the cup holder, hold the cover in place and give it a few good bangs with your hand. Should snap back in. The rear internal sensor can be found by removing the rear cargo floor and tray, just as if you are accessing the spare tire. You'll see a similar white box down there on the drivers side near the rear seat back.

Rob

 

Maybe try to disconnect the center console sensor and try to test again? That way you concentrate your efforts on that one sensor......not the door sensors.

 

Yeah, the door sensors are hard to get at. I think focusing on the inside sensors makes sense.

I don't know what to make of the panic button not working. I'm really hoping you just have a bad sensor or fob. If its the security ECU my understanding is that is a real pain, and quite expensive as I believe you have to replace multiple ECUs at the same time

I don't know if its the only way, but here is an example of what I understand it to take to "rekey" a Prius:
DISCOUNTED INSURANCE SALVAGE
Steve's kit here is a used match set of immobilizer ECU, Smart Key ECU, Engine ECU, HV ECU and two fobs for $695. I'm sure new parts would be much much more. I could be wrong, but my understanding is that if you need to replace one of these ECUs you have to replace them all with a matched set so they will talk to each other. I'm assuming this is intended to keep someone from quickly/easily being able to defeat the security system by just swapping one ECU?

Rob

 

Ok, that would seem to rule out the inside sensor. Hopefully when your new fob comes that will help!

 

It might also be good to pick up a "mini-VCI" adapter from ebay/amazon. There are a number of threads discussing these. They run about $30 US, and are a Chinese knock off of the official Toyota diagnostic interface including the techstream software. This will get you much more visibility into what the car is reporting, and if you subscribe to TIS to get access to the factory service manuals you will have the ability to follow their debug flowcharts exactly as the dealer technician would. I believe the it also gives you the ability to do things like reprogram key fobs, and other security related functions that might be handy. Its a very powerful tool to have if you are doing your own work on a Prius!

Rob

 

Thank you so much. I have gotten so much thru this site.