Toyota tundra key fob scenario

[Dermako]

Have a 2008 Tundra with about 285k on it. Has been the most reliable light duty truck I’ve ever owned without question.
On a recent road trip I arrived at destination and unloaded. As I am walking away I push the lock button on the key fob and nothing. I walk back to truck and try again. Still nothing. Don’t think much of it other than I need to replace battery in key fob. I manually lock the doors and go about my day.
End of day rolls around and I forget and key fob won’t unlock doors. Use key
no problem. Get in truck and it turns over but will not start. Problem. Other than a dead battery has this vehicle never not started.
Get to talking to a coworker and he asks about smart key. I am pretty sure it is not. But smart fob? Well on the way to hotel we stop at Walgreens I get a new battery for the fob. Next morning I am anxious to see what happens. I walk up to truck and hit unlock and it unlocks. That’s a plus. Put key in and dam thing starts. I would never have thought a dead battery in a key fob would disable that truck.
I have replaced the battery in the fob at least once before but it wasn’t dead. I just had to very close to the truck for it to lock/unlock so I knew it needed to be replaced so I never had this issue before.
Been driving it daily for about a week since it happened without a problem so I am pretty sure that was all it was.

 

[crystalphoto]

My Mazda car does the same thing when the battery goes dead in the fob...It has something to do with the car detecting the fob, maybe has to do with anti theft... I keep a spare battery in the glovebox.

 

[Lonesome Dove]

My 08 Tacoma hasn't worked for about 5 years nor does my cruise controle. I don't need either so it doesn't bother me.
I disconnected my alarm and I just use the key for entry except I have to double twist it to unlock the back doors.

 

[Dermako]

My mom has my dad’s 07 Tacoma and if I think about it the next time I am there I am going to pop the battery out of the fob on it and see what happens. Curious now.

 

[Tnhawk]

When the key fob battery died on my 16 Tacoma, it wouldn't start. I now change the batteries in all my key fobs every other year.

 

[Younggun]

Most vehicles have a warning on the dash to notify of a low battery if the fob is required to start it.

 

[Tnhawk]

Most vehicles have a warning on the dash to notify of a low battery if the fob is required to start it.

The Toyota didn't give a warning, just stopped working at inconvenient time. I don't want to have that happen again. Easier to change battery on my schedule than get a suprise.

 

[TipBledsoe]

A fob is not very important to me - not using and carrying around the fob has never been an inconvenience or caused a problem for me. I just leave the fob behind.

I already have enough things on my key ring, and I don't mind using the key to unlock my doors - besides, I will already have the key ready to insert into the ignition switch.

Interestingly, not having my fob has never caused the problem the OP describes. Apparently the truck computer pings for the fob when the ignition switch is activated. Obviously the truck will sense a fob with a good battery and all is well. Apparently the truck can sense a fob with a dead battery and all is not well. And apparently the truck can sense no fob and all is well.

... I wonder and suspect, during the problem, if @Dermako would have tried leaving the fob far enough away and tried starting the truck if it would have started with no problems.

 

[Dawico]

Most vehicles that require a fob have a location to place the dead fob that will allow the vehicle to start. Check your owner's manual or do a search.

My daughter's Jeep says to use the dead fob to push the start button to override a dead fob battery.

Some vehicles have a slot in the center console to place the fob in the same situation.

Just a few options I have seen.

 

[Dawico]

A fob is not very important to me - not using and carrying around the fob has never been an inconvenience or caused a problem for me. I just leave the fob behind.

I already have enough things on my key ring, and I don't mind using the key to unlock my doors - besides, I will already have the key ready to insert into the ignition switch.

Interestingly, not having my fob has never caused the problem the OP describes. Apparently the truck computer pings for the fob when the ignition switch is activated. Obviously the truck will sense a fob with a good battery and all is well. Apparently the truck can sense a fob with a dead battery and all is not well. And apparently the truck can sense no fob and all is well.

... I wonder and suspect, during the problem, if @Dermako would have tried leaving the fob far enough away and tried starting the truck if it would have started with no problems.

You leave your fob in the vehicle or at home?

If the vehicle doesn't detect a fob at all it shouldn't start, same as a dead fob battery situation.

 

[TipBledsoe]

You leave your fob in the vehicle or at home?

If the vehicle doesn't detect a fob at all it shouldn't start, same as a dead fob battery situation.

I leave my fob behind… at home.

My 2011 Tundra has no starting problem without a fob - as I said, apparently the truck can sense no fob and all is well.

Please give it a try - leave your fob more than 100’ away and see if you can start your truck with just your key.

 

[TipBledsoe]

Most vehicles that require a fob have a location to place the dead fob that will allow the vehicle to start. Check your owner's manual or do a search.

Some vehicles have a slot in the center console to place the fob in the same situation.

I suspect that such a location is essentially Faraday cage that prevents the vehicle from “seeing” a fob.

My suspicion is that such an ability is essential for vehicles having a fob, because your fob with a dead battery likely just “looks” a lot like an unauthorized fob.

Please try leaving your fob more than 100’ away and see if you can start your truck with just your key, and let us know your results.

 

[Younggun]

I suspect that such a location is essentially Faraday cage that prevents the vehicle from “seeing” a fob.

My suspicion is that such an ability is essential for vehicles having a fob, because your fob with a dead battery likely just “looks” a lot like an unauthorized fob.

Please try leaving your fob more than 100’ away and see if you can start your truck with just your key, and let us know your results.

Maybe yours just doesn’t communicate with the fob for starting.

 

[toddnjoyce]

I suspect that such a location is essentially Faraday cage that prevents the vehicle from “seeing” a fob…

Usually the passive (and sometimes transponder) key/fob holds an RFID chip that’s energized by antenna’s radiated power. The antenna is located in the spot manufacturer states to put the ‘dead’ or passive key/fob at.

This is much like the chip on your debit/credit card. The chip is activated by the card reader energizing an ultrathin antenna embedded in the card that connects to chip.

 

[Dawico]

I leave my fob behind… at home.

My 2011 Tundra has no starting problem without a fob - as I said, apparently the truck can sense no fob and all is well.

Please give it a try - leave your fob more than 100’ away and see if you can start your truck with just your key.

My fob is on the key itself so not an option.

Neither of my daughter's jeeps will start without the fob present, but they're both push button start.

You must have a chip in your key that allows it to work without the fob present.

 

[striker55]

Most vehicles that require a fob have a location to place the dead fob that will allow the vehicle to start. Check your owner's manual or do a search.

My daughter's Jeep says to use the dead fob to push the start button to override a dead fob battery.

Some vehicles have a slot in the center console to place the fob in the same situation.

Just a few options I have seen.

My Impala has that, a slot to put the fob when the battery dies