Rear parking sensor muting

[Gambit1870 Lurker Find all posts View Profile Close Gambit1870]

Hi,
Can somebody tell me if the rear parking sensors are muted when a trailer is connected?

Have spoken to 2 towbar suppliers and one said yes, the other no

This will be on a 2021 VX

Thanks

[RPP Senior Member Find all posts View Profile Close RPP]

The sensors spring into life at somewhere around a metre.
A trailer isn't likely to be close enough, otherwise all caravans and trailers would set them off.

[Gambit1870 Lurker Find all posts View Profile Close Gambit1870]

Would they not detect the draw bar?

[RPP Senior Member Find all posts View Profile Close RPP]

Don't know. Interesting question tho'.
If they did all caravans and trailers would set them off.
The ground gets closer and that doesn't set them off.

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

Aftermarket reversing sensors certainly do go berserk when reversing with a trailer or caravan. There are all sorts of things on the tow bars of trailers and caravans to generate an ultrasonic echo.

I have a reversing camera mounted on my caravan. I mounted a sensor on the trailer socket cover witch causes the reversing camera source to switch from the Prado's OEM camera to the trailer's aftermarket camera. The circuitry also disconnects the reversing light input wire to the aftermarket parking sensor controller, shutting the parking sensors off when the socket has a trailer plugged in.

[Not Enough Time Junior Member Find all posts View Profile Close Not Enough Time]

The parking sensors remain active in my August 2021 GXL when you have a trailer connected with a genuine Toyota Tow bar fitted by a dealer. I'm disappointed, I thought that would have been part of the harness set up. You need to deactivate the parking sensors at the switch at your left knee, then remember to switch it back on when you have ceased reversing (which I fail to do most of the time)

[Gambit1870 Lurker Find all posts View Profile Close Gambit1870]

Aftermarket reversing sensors certainly do go berserk when reversing with a trailer or caravan. There are all sorts of things on the tow bars of trailers and caravans to generate an ultrasonic echo.

I have a reversing camera mounted on my caravan. I mounted a sensor on the trailer socket cover witch causes the reversing camera source to switch from the Prado's OEM camera to the trailer's aftermarket camera. The circuitry also disconnects the reversing light input wire to the aftermarket parking sensor controller, shutting the parking sensors off when the socket has a trailer plugged in.

Thanks, that's what I was looking for.
Disappointing that Toyota haven't thought of this, my 2018 Ranger automatically muted the sensors once it detected the trailer plug was connected.

Can you give me some info on the sensor you're using thanks?

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

Thanks, that's what I was looking for.
Disappointing that Toyota haven't thought of this, my 2018 Ranger automatically muted the sensors once it detected the trailer plug was connected.

Can you give me some info on the sensor you're using thanks?

I would suggest one of these Narva | 7 Pin Flat 'Quickfit' Trailer Socket with Reed Switch for use with Normally Open C or one of these Narva | 12 Pin Flat Trailer Socket with Reed Switch for use with Normally Closed Circuits, particularly if you have 'flat' sockets already. The 7-pin switched socket starts at around $30 while the 12-pin version is probably more than double that.

The limited wiring diagram supplied on the Narva website shows one end of the reed switch connected to pin 3 (ground or 0v) and the other extended with an additional wire, presumably to the interior of the vehicle. This wire would need to reach all the way to near the dashboard switch that is used to turn off the reversing alarm. Unfortunately my vehicle has aftermarket reversing sensors, so I don't know what the Toyota dashboard switch actually does. The trailer socket switch would probably need to operate a small relay (+12v IGN on the other side of it's coil). Switched contacts of the relay would need to duplicate what the dashboard switch does. The wiring diagram appears the show Light Bue and Violet wires going to the switch. Apologies for the vagueness of my reply here.

Unfortunately, I have not been able to find a switched round socket.

I'm a (semi) retired electronic engineer, so I have an unfair advantage. I have a 7-pin small round plug/socket on the Prado. I attached a small bracket with a 'super' (neodymium) magnet to the spring loaded cover of the socket. This gets close to a hall-effect sensor when the cover is opened. All a bit over-the-top for the average Prado owner.

[Gambit1870 Lurker Find all posts View Profile Close Gambit1870]

I would suggest one of these Narva | 7 Pin Flat 'Quickfit' Trailer Socket with Reed Switch for use with Normally Open C or one of these Narva | 12 Pin Flat Trailer Socket with Reed Switch for use with Normally Closed Circuits, particularly if you have 'flat' sockets already. The 7-pin switched socket starts at around $30 while the 12-pin version is probably more than double that.

The limited wiring diagram supplied on the Narva website shows one end of the reed switch connected to pin 3 (ground or 0v) and the other extended with an additional wire, presumably to the interior of the vehicle. This wire would need to reach all the way to near the dashboard switch that is used to turn off the reversing alarm. Unfortunately my vehicle has aftermarket reversing sensors, so I don't know what the Toyota dashboard switch actually does. The trailer socket switch would probably need to operate a small relay (+12v IGN on the other side of it's coil). Switched contacts of the relay would need to duplicate what the dashboard switch does. The wiring diagram appears the show Light Bue and Violet wires going to the switch. Apologies for the vagueness of my reply here.

Unfortunately, I have not been able to find a switched round socket.

I'm a (semi) retired electronic engineer, so I have an unfair advantage. I have a 7-pin small round plug/socket on the Prado. I attached a small bracket with a 'super' (neodymium) magnet to the spring loaded cover of the socket. This gets close to a hall-effect sensor when the cover is opened. All a bit over-the-top for the average Prado owner.

Thanks for the informative response mate, I'm an I&E Technician, so understood your explanation. I'll have to hunt down some schematics for the Prado's electrical system. I'm guessing it'll be some sort of Can Bus system these days?

I'm running flat 7 pins so should be a straight swap with some extra wiring, I might run a multi core from the rear to the front when I get around to running power for the trailer etc future proof for later mods.

Cheers

[GeeWhizz Senior Member Find all posts View Profile Close GeeWhizz]

....I'm an I&E Technician, so understood your explanation.

Hey - we talk the same language! The attached screen snip is for 08/2017+ Prados. While there is an ECU for the Parking Assistance system, the control is just down to that one switch. You could either place the relay contacts in series with the +12v input (cut the light blue wire) or parallel with the existing switch (between the Lt Blue and Violet wires). I wouldn't play around with the Buzzer wiring because it might also be used for other functions.

[Gambit1870 Lurker Find all posts View Profile Close Gambit1870]

Thanks mate appreciate that

Think I'll just parallel the switch, I'll do a bit more investigation once I get the vehicle on Wednesday.
Nothing like cutting loose with a pair of side cutters on a brand new car

[HappyChappy Lurker Find all posts View Profile Close HappyChappy]

Thanks mate appreciate that

Think I'll just parallel the switch, I'll do a bit more investigation once I get the vehicle on Wednesday.
Nothing like cutting loose with a pair of side cutters on a brand new car

Hey mate,

Not sure if this will help, but in my 2020 GXL I have a switch on the LH switch bank next to the steering wheel that will disable the rear parking sensors completely. Your2021 VX will have this for sure. This is the same bank of switches that house the DPF burn button.



What did you end up doing?