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"Key detected in vehicle" Error displayed while car is driving?

38753 Views 17 Replies 12 Participants Last post by  dwilco
Hello all,

Beginning about three days ago, my ct has been giving me "key detected in vehicle" while the car is moving. This started to happen after the temperatures here have gotten to approximately minus 30 Celsius and mainly happen after the car detects slippage in the snow. I'm thinking this might be a problem due to the extreme cold temperatures. Also the problem seems to have worsened as when the message is being displayed, my doors will unlock themselves and the dash light will flash on and off.

Has anyone else had this problem or have any ideas? I called the dealers and they said it might be the battery getting low, but to me it doesn't seem like the cause because it only occurs after the tires slip and in very cold weather.
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Hello all,

Beginning about three days ago, my ct has been giving me "key detected in vehicle" while the car is moving. This started to happen after the temperatures here have gotten to approximately minus 30 Celsius and mainly happen after the car detects slippage in the snow. I'm thinking this might be a problem due to the extreme cold temperatures. Also the problem seems to have worsened as when the message is being displayed, my doors will unlock themselves and the dash light will flash on and off.

Has anyone else had this problem or have any ideas? I called the dealers and they said it might be the battery getting low, but to me it doesn't seem like the cause because it only occurs after the tires slip and in very cold weather.
Normally the message indicates a battery that is getting low. But in your case -30 C is very cold for batteries to work at full potential. I don't think the snow slippage is directly related; just another result for your -30 C and the snow and ice at that temperature.
Try putting in a new battery. It takes about 60 seconds (make sure you have a replacement) and costs peanuts - why not give it a go? It's not cold here today (97 degrees) but the display kept showing "Key not detected" until I changed the battery.
MissPharmer: where do you live? I am in Winnipeg and have had my CT Since April 2011. I have been in a few -30C mornings and haven't had any issues other than the LCD screen on dash (I have non nav) getting a bit slow if you cycle between displays (but I don't really anymore). In that weather my worst mileage was 7.8l/100 (or 34 US mpgs).
I took my ct in to the dealer yesterday afternoon and of course it stopped having the problem that very morning, although it happened still the night before then. I took a ride with the service fellow but was unable to produce the error. He checked the battery in key by pressing and holding the lock button and did not find it to be low. The error hasn't come up since so I'm hoping it was just a minor thing and won't pop up again!
If it happens I will try switching out the battery and shutting the hatch firmly. Thanks guys!
Hey coubs, I live in Winnipeg also and I also have the problem With slow cycling between the screens during the winter. I'm getting about 7.8to 8.3L/100 in the winter. Do you have snow tires installed? With the blizzard last Saturday, I wasn't able to make it one block away from my house before getting stuck, ended up cabbing it to work (I have factory all season tired).
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Woot a feelow Winnipeger! I have only seen 2 CTS in almost 2 years here - is yours Fire Agat or the Blue Fsport (I see that one out my office window a lot as they work at or pick up/ drop off at the IBM building.
I get no higher than 6.6 or 6.8 but like I said my car is warm most of the time because it is in an insulated garage at home and heated underground during the work day. The biggest killer is that the engine is almost always on even at complete stops until it warms up enough - and that depends on how high you set your heat. I used to actually shut off my heat at stop lights and the engine would stop and I would get down to 6 or even 5.8/9. for the last month or two I use auto and teh temp is at 22C but I still will turn it off when I am 4 or 5 blocks from work or home and can usually keep it in EV mode most of the time and lower my L/100.
I do have snow tires - I got the Good Year Nordics from Can Tire and put them on some Sacci alloy wheels (16 inch too for potholes in the spring) and they make a HUGE difference (there are lots of posts about winter tires on this forum).
Ah that Blizzard! I shovelled for an hour Saturday morning then walked around our bay and knew that I would get hung up - the tires would have been okay but the ground clearance on our CT's are so low that the 6 or 8 inches of snow between the ruts in the road would have hung me up for sure.
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Same thing happened to me a while back. Another CT200h owner was riding with me - his key fob was confusing my car :)
Woot for minus 40 temperatures! XD I think I've only seen a silver one in a parking lot on Sargent. I drive a pearl white 2012 with touring package. TheSe days I'm only able to get 8.8-8.9, although I do heat my car for ten minutes in the morning And blast the heat to the max... I don't like the cold very much! I used to always keep it in Eco mode but After reading posts on the forum I've decided to give normal mode a try as people say the fuel economy is about the same, and it is painfully slow to drive in Eco. In the summer I was able to keep the car in ev mode because I go thru a lot of start and stop traffic and got 4.6-5.6. But a strange thing I found was that it seemed to progressively get worse over time. I could imagine snow tires would be much better, I was wondering About the tire pressure monitoring if I were to switch the wheels though.. I'm sure there are many posts about this as well, must do research now! ��
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Same thing happened to me a while back. Another CT200h owner was riding with me - his key fob was confusing my car :)
If thats for real then that's a serious bug.


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I just got back from St. Lucia and missed the minus 40's so thankful that my CT didn't have to experience that - yet! ;)
Idling before driving kills the mpgs but yes it is worth it to be warm I think - and the heated seats are awesome.
Yeah in the summer I can get out of downtown in EV only until I start going up the Disrelli bridge but it is nice not to use gas for part of the commute home.
As for the TPMS: I didn't get them put on the winter rims and the low tire pressire light comes on and sometimes blinks (I think it resets as the summer tires in the garage beside my park so it registers every day) but it is not that big a deal - and hopefully the summers can go in in a month, or two, or...

I'll be looking for the Peral White touring CT in the peeg now!
If thats for real then that's a serious bug.


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Actually, it probably is real. My wife has a Prius, Now she has both, and when she would get in the Ct200h with her Prius key on her, the CT200h WOULD NOT START. You can get some relief using the electronic Faraday effect; put the extra transmitter in a metallic enclosure like the plasticized metallic envelopes electronic computer parts are shipped in. Lexus has a fix, if this error occurs, but they have to replace both key transmitter and the car receiver. They have to order then take a leisurely two hours to install; no one ever said Lexus was fast and efficient.
...Lexus has a fix, if this error occurs, but they have to replace both key transmitter and the car receiver. They have to order then take a leisurely two hours to install; no one ever said Lexus was fast and efficient.
I supposed this is covered under warranty?

Regarding the "plasticized" bag (a.k.a. anti-static bag), I use it for a spare electronic tag to stop it from beeping (and being charged) when going through a tollway if the vehicle already has one.
I have had the exact same thing happen with my vehicle recently. It's a 2012 RX350 I've gotten the "key detected in vehicle" while the car is moving, my doors will unlock themselves and "Key Detected in Vehicle". The message stays on for a bit, then goes off on it's own. Just yesterday I got a that the back door was open, the interior lights come on & the chimes sound. All of this while the vehicle was in motion. I've noticed it happening or possibly being triggered by going over bumps in the road. Were you able to find out how to fix it?
This just started happening today to my rx350. It is really cold today so wondering if that has something to do with it?
After reading 100's of posts and finally going on a 45 minute drive with constant alternating ".* Key detected in vehicle"**warning alternating with "rear door open" warnings and 45 minutes of constant beeping.* I knew I had to come to a*conclusion.** Either find a fix, or drive the vehicle over a cliff.
* I searched 100's of posts of people spending money, time, and energy at the dealer attempting to* find a fix*with very little luck among any of the posters.
.* I ended up fixing the problem for 48 cents.
.* I was unable to find the original post that recommended this*, so that I could*thank the person* that came up with this idea, but I will pass it on.
*First, I took electronic spray cleaner and thoroughly sprayed the inside of the rear hatch door latch.* There is a small rectangular carpeted cover the can be easily removed with a flathead screw driver to allow you to spray into the latch itself.* This definitely improved, but did not fix the problem.** You can get electronic contact spray cleaner at Walmart or RadioShack.
**You then*need to buy*1/4 inch lock washers.* This cost me 48 cents.
*Open the rear hatch door, and on both sides of the bottom of the door you will see, rubber bumpers sticking out from the door.
*Look down by the rear bumper where those rubber bumpers hit when the door is*closed.
* With a Phillips head screwdriver, remove the*rubber washers down near the rear bumper.
*Place two lock washers under each of the*rubber washers*to help raise them up and screw them back into place.
* I have driven over speed bumps, I have gone over a curb and no alarms have gone off.* Prior to this fix I could not hit a pebble in the street without an alarm going off.*** For a year, *I have been dealing with this problem and it only took 48*cents to fix it
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I wanted to chime in and say that this happened recently to me as well. It was not very cold, nor was I going over any terrain I've never gone over before. The only thing that was out of place was a "key fob battery low" message I got ONCE, then it never came back. (Previously, if my key fob battery was low, it would indicate and keep doing so until I changed it.)

Since the message came on only one time, I thought it might be the beginning stages of a low battery and left it alone. It wasn't till weeks later that this happened, and only 2 times total.

I have since replaced the key fob battery and it has never happened again.
I had this too until it drove me mad and replaced the battery.
With the tailgate problem it would be easier to just slightly lower the striker a bit so the hatch closes tighter.


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I posted this answer to the problem in December 2016.
I have added an addendum because the problem began to recur

Buy*1/4 inch lock washers.* This cost me 48 cents.
*Open the rear hatch door, and on both sides of the bottom of the door you will see, rubber bumpers sticking out from the door.

*Look down by the rear bumper where those rubber bumpers hit when the door is*closed.
* With a Phillips head screwdriver, remove the*rubber washers down near the rear bumper.
*Place two lock washers under each of the*rubber washers*to help raise them up and screw them back into place.
* I have driven over speed bumps, I have gone over a curb and no alarms have gone off.* Prior to this fix I could not hit a pebble in the street without an alarm going off.*** For a year, *I have been dealing with this problem and it only took 48*cents to fix it

Addendum:
I did have a recurrence of the problem after the above fix, but not as bad. At Home Depot, I obtained #14 1¼" screws. I ended up putting three 1/4" lock washers underneath. It has again cured the problem. With the 1-1/4" screw, I can always add another washer underneath if it recurs again. Total cost, less than $1 to fix the problem.
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