Aftermaket reversing beepers

[Toobs]

So the corolla i just got has at some point had reversing sensors fitted which don't seem to work.

When reverse is selected there's one long beep, and then just intermittent beeping no matter what's around. Anyone had anything like this?

I'm pretty sure it's not factory fit/toyota system.

[oldcodger]

Fitted some to my 2006 model about 7 years ago, still working well, just cheap eBay ones .

Typically you have a display unit which sounds and flashes some distance indicator leds and a small control box, usually fitted down by the rear light clusters, where water can collect !

When reverse is selected that applies power to the circuit and so your single bleep, about 1-2 seconds on mine.

If you move by the sensors it should alarm , so if not,   the first thing to check are the wires from the sensor to the control box.

Assuming all 4 sensors do not work, would look at the control box end first.

[Toobs]

I'll check it out. Thanks.

[Gerg]

It would seem to be the case that the sensors are pulsed by the controller every half second or so.  As a very rough guide to a proper connection to the bumper sensors, if you put your finger onto the centre portion of each of the sensors you should feel it buzz momentarily every half second(-ish) when it's operating.  This is more easily felt with your finger nail.

Some years ago I had some aftermarket (Cobra brand, same as the alarm company) sensors mis-triggering intermittantly.  I read on a forum that someone with a similar problem had used a very short squirt of WD40, directed in the direction of the circular gap in the sensor head, that had fixed the problem for a while.  I was a bit disbelieving, but I tried this, and when the car was sold 2 years later the fault had not reappeared, odd.  But the same attempt at a fix made chuff-all difference to a failing OE VW sensor on a different car.

On the sensor kits I've fitted, a sticker on the controller warns against disconnecting the sensors with the unit in operation, as it can damage the unit.  I don't know if they all can suffer similarly.  And In the cheaper kits the instruction warn that if the sensor is too tight in the hole that it can give a false reading, but this seems to settle down over time, so probably not your problem here.  Given that all the sensor holes are made with the same drill bit, this advice in the instructions is a bit perverse.

On another install I had to mix a Valeo (quite expensive kit) with the controller from an Amazon budget kit.  It all worked perfectly.  So it would seem there is some (unintentional!) electrical compatibility with certain aftermarket kits. Those two kits had the same connectors/sockets fitted, which made it all easy.

HTH