Mysterious Button Near Gear Shifter

[Romasato]

Hi there,

Maybe someone could shed some light on what this button is for? Was there when I bought the car a few months ago and still haven't figured out what it is supposed to do - clicking on it does not change anything noticeable in the functionality of the car. Also, it has a red LED which seems to be on when I start the car.

Any info would be appreciated! Thanks

[katabrontes]

I am pretty sure it's to switch off the parking sensors. I have a very similar button on my RX350 (but not in the same place) and this is what it does. I find the sensors bleep in the rain and when a motorbike overtakes me. Also sometimes randomly on motor ways. Apart from the rain which is a recognized feature of these sensors I assume bikes must have some electronic devices that trigger the ultrasonic sensor. They will be an aftermarket set as the original Lexus sensors only work at slow speeds. Your reversing sensors are probably switched on only when you select reverse so are not affected.

[timbest4]

Its to lock out the gear shift when the car is jacked for towing, its not for the parking sensors, that switch is on the multifunction on the steering wheel

[katabrontes]

Re TIMBEST4 I don't think this is correct. The lockout button is the one at the top right of the photo and the round one with the red LED (to which this post refers) is for the parking sensors. Tim must have the original Lexus sensors which are switched differently. The photo shows an after market set-up and it is clear form the wire coming out beside the round insert that this was fitted later and is not original equipment.

[Romasato]

That is true - the car has rear parking sensors which work fine and are activated when reversing. Strangely, my front ones do not work - the car has them though. Clicking on the button does not enable them either, so I am guessing the sensors aren't working at all or the button (snapped wire somewhere?) does not.

In any case - was wondering - where would be the sensor box/computer located? Just to check if it is there at all.

P.S. There is no tow bar on the car. The "SHIFTLOCK" button is for a different purpose, I quote one reply from another forum:

"The button is used to bypass the U.S. mandated shift lock. In the U.S., all cars must be designed so that you cannot shift out of Park unless the key is in ignition and foot on the brake."

[Dewey]

Where is the button to turn of the rear parking sensors?

[Romasato]

Where is the button to turn of the rear parking sensors?

I don't think there is - at least in my case - as the sensors start working once you shift into [R]everse.

[ColinBarber]

normally you don't have a reason to turn off the rear sensors as they only become active when reverse is selected. I would think the switch is purely for the front sensors as it is often desirable to disable them in traffic etc.

[Boxbrownie]

You say the LED is on when you start the car, so

1 is the light off when ignition is off and car locked?

2 when you start the car is the light on continuously or does it go off once the car is running?

3 if you have to manually turn the LED off does it come on again "automatically" the next time you start the car?

4 Are there any other aftermarket looking accessories on the vehicle you know about ie tow bar, power sockets etc?

The two most likely answers to its purpose is front parking sensors or an aftermarket alarm or immobiliser.

Quick question, if you have a tow bar do the rear parking sensors still work when in reverse and the lamp is activated (or deactivated) ?

[eskezz]

Write/contact the previous owner-usually the best solution.

[Romasato]

You say the LED is on when you start the car, so

1 is the light off when ignition is off and car locked?

2 when you start the car is the light on continuously or does it go off once the car is running?

3 if you have to manually turn the LED off does it come on again "automatically" the next time you start the car?

4 Are there any other aftermarket looking accessories on the vehicle you know about ie tow bar, power sockets etc?

The two most likely answers to its purpose is front parking sensors or an aftermarket alarm or immobiliser.

Quick question, if you have a tow bar do the rear parking sensors still work when in reverse and the lamp is activated (or deactivated) ?

Hi Boxbrownie,

To answer your questions:

1. When ignition is off and car is locked, light is off.
2. When I move the key into the READY position, it lights up brightly and stays that way while the "READY" mode initial beep is being played. Once the beep ends, light goes dim, but stays on, but very faintly.
3. Clicking the button has no effect on the LED, so nothing changes after car is switched off and started again. I even tried holding the button while moving the key into READY mode, but still no effect.
4. No other equipment besides standard.

So I am quite baffled at this point about what that button is for - I will probably try removing the middle gear/console covers to see where the wires go - maybe it is related to iPod integration or smth? Hmm...

[Boxbrownie]

Hm, I had a car with a mystery button which acted similar to yours, turns out it was an alarm system had been added in the past but did not work anymore, seems odd anyone would fit one on a car which already has a Thatcham approved alarm factory fitted.

[GUNGAABAYAR]

On 04/09/2014 at 2:27 PM, Boxbrownie said:

Hm, I had a car with a mystery button which acted similar to yours, turns out it was an alarm system had been added in the past but did not work anymore, seems odd anyone would fit one on a car which already has a Thatcham approved alarm factory fitted.

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[rynd2it]

The rear sensors can be disabled (when towing for example) with a switch mounted on the right side of the luggage compartment - it is marked with a red sector so you can tell when on/off. The front sensors have small button with an LED (like the one above) usually mounted on the right side of the dash about knee level. That's where the installation instructions say it should me and mine is. When pressing it with the ignition on it should beep twice and then the sensors are disabled BUT they revert to being enabled as soon as the ignition is switched off and then on again (PITA). I am hoping to get mine sorted tomorrow as they are on even if the gear is in Park which is wrong, they should only work in Drive and at certain slow speeds. I have all the factory installation stuff for these LPA800 kits but it is pretty sketchy and involves some wire splicing which I suspect in my case was not done correctly.