The remote control/smart key fob contains a mechanical key that unlocks the driver's door. But if I had to use it because of a dead fob battery, how could I start the car, a 2005 Prius? The instruction manual warns about not discharging the battery, recognizing when the charge is low, and tells how to replace the battery. But a fob battery could be discharged by forgetfully leaving it sitting close to an rf source that would repeatedly cause the fob to broadcast its code till the battery ran down. Could the car be started by inserting a "dead" fob into the dashboard Key slot?
Just stick it in the slot, it doesn't require the battery to start there. Just for the remote and SKS.
mechanical key opens the door. then stock the FOB into the dash. the car should run a charge through it to verify it's the proper fob, then enable the car to turn on.
Thanks for your quick responses, Evan, V8CobraKid, and Batabier! Sounds logical, but one statement in the "2005" Owner's Manual (seems to be for the 2004, with only the cover changed!). On page 25 the topic "Alarms and Warning Light" is discussed in several subtopics, (a) through (j). Subtopic (h), Low smart key battery, states "When the hybrid system is turned to "ACC" or "OFF" about 20 minutes after the hybrid system is turned on or to "IG-ON", it is determined that the smart key battery voltage is low." I interpret this to mean " IF the hybrid system turns ITSELF to "ACC" or "OFF" about 20 minutes - - - THIS SIGNIFIES that the smart key battery voltage is low." (I don't think the driver would turn the "ACC" or "OFF" about 20 minutes after ---). The implication is that a robust smart key battery is required to keep the hybrid system running indefinitely. But that seems inconsistent with the ability to start the hybrid system with a dead fob battery! One explanation could be that, if the car is entered and started with the smart key in the driver's pocket (not in the slot), the car keeps interrogating the smart key while one is driving along, which could deplete an already marginal battery so that it fails to respond to the car's interrogation. The car would then think the smart key was absent AND thus not in the slot, and the hybrid system would turn itself to "ACC" or "OFF". That would be logical, if somewhat dangerous. If this explanation is true, it would seem wise to put the fob in the slot, even if the smart key feature was used to enter the car! Wot say, dear experts?
No, the SKS quits sensing for the Fob after a period of time...I don't have my Owner's manual handy, but I can tell you that I think what it's saying in that section is that the sks turns off and stops sensing...what, exactly, that has to do with a low fob battery I don't know. But we do know that an active sks fob is NOT a requirement for the car to keep running...in fact, once the car is in Ready mode you can drive until you run out of gas without a fob at all!
Remeber, It is a better version of Ernglish, a Japanese to English translation. It didn't say "when the hybrid turns to acc or off", it said "when the hybrid IS turned to ACC or off", in other words somthing else (you) turned it to acc or off. If the car is turned to READY or IG-On at least 20 minutes after the car remained off or ACC, it will check the battery condition of the fob and warn you if it is low. You can experiment and see when the fob is responding to an SKS interrogation. You will see a red LED light up in the upper righthand corner of the fob when it transmits. The car will continue to run, even if the fob is removed from the vehicle, as long as it is not powered down. It will complain, but it will run, so a carjacker doesn't need your fob to throw you out of the car and drive away. Once he powers off though, he will not be able to start it again.
Thanks again, guys. Danman: I have learned not to trust implicitly the translations in the user's manual! So I didn't miss the "is", but I was focussing on the driver wanting to drive for MORE than 20 minutes after turning the hybrid system ON, so assumed (erroneously) he wouldn't turn the HS to ACC or OFF. I think your interpretation (that if the car has been OFF for over 20 minutes, the next time it's turned ON, the low battery check is made), is incorrect (is not what the manual says). I now think the manual is saying, if one has been driving for over 20 minutes, the next time one turns the HS OFF, the car checks for low fob battery and sounds one short beep inside if the battery voltage is at or less than 2 volts. (I left out the IGN-ON and ACC states, for clarity.) If one turns OFF the HS after driving, say, only 10 minutes, the battery check is not made. This is finally beginning to make sense, at least to me!
Without proper commas, the wording in the user manual could be interpreted either way. I checked the repair manual, and it seems you are correct. Detection conditions (verbatum): If condition listed below is met, and smart ECU receives code indicating voltage drop of smart key battery while room oscillator checks smart key ID code: The power switch has been turned OFF after 20 or more minutes have elapsed after hybrid system has been started.
