Rear parking sensors and available types.

[Ozzie]

The outer ones require the removal of the linings in the wheel arch. They are a O with a "+" across it, like a sight on a rifle  I will measure my sensors later on, so you know where it is likely to be.

OK had a quick measure, inner sensors are 61cm apart and 44cm from ground, outter sensors are 131cm apart and 57 cm from ground (roughly in line with brake light bulbs), quite a bit higher than the inner sensors, I hope that helps.

Ozzie

[chrisc]

There is a Chinese importer near where I live selling the ultrasonic parking assist kits for R 350,00 (about £30)

Diabolical English instructions, but easy to read diagram.  Going to fit these to a Hyundai and won't have to remove the bumper

[Oldie]

The reason I was planning to go for the Steel Mate (about £72 delivered in UK) was that I have read warnings on other sites that there are very cheapo sensors available which are not always reliable. My reasoning is that given the effort of fitting sensors not to mention the cost and time involved in colour coding them, I will pay what it takes to get good quality. Of course where you are located, the price comparison is difficult but I do still believe that you get (hopefully) what you pay for.

Poor deluded fool!

[Oldie]

Ossie,
 Thank you very much,  I have just read you edited post with the sensor location dimensions - very useful information. I have noted that you have a 2011 Hybrid and I believe that the positioning on this is not the same as my 2009 1.4 ES (from the Honda brochure pictures), my model is shown as having the sensors in a straight line so if it is my lucky day, I won't need to remove the inner wing panels.

I could be mistaken but I believe the rear bumper skirt is a different shape on the newer models especially the Hybrid.

[Ozzie]

D'oh 

[chrisc]

Fitted the 4 ultrasonic sensors to the Hyundai quite easily.  Not mentioned in the book is that there is a trimmer inside the controller.  This had to be turned down to about nearly off to prevent the devices from detecting a leaf 5 metres away.

[Oldie]

Chrisc - well done, it looks very tidy and professional. Do you intend to colour-match the sensors in place or leave them black?

Having looked hard at Honda brochures for my Jazz (1.4 ES 2009) the spacing of inner sensors appears to be around either 40cms or 50cms I have seen both illustrated. The outer sensor spacing would seem to be more critical because of the existence of chassis outriggers each side behind the rear bumper (one has the concealed towing eye thread behind a circular cover plate) and according to my measurements 113cms is a minimum spacing but DO CHECK behind for sufficient clearance for the sensor before drilling. You have been warned. I am not accepting responsibility for wrongly drilled bumpers!!!

Since the sensors apparently work best if their radiating face is vertical, it looks like positioning them in an approximately straight line just below the ridge that runs across the bumper is favourite and using an angled collar to compensate for the 10 degree-ish sloping face of the bumper could achieve this.

I am still "giving it a coat of looking at" before deciding to take the plunge!

Good luck though if you do decide to have a go.

[Downsizer]

My sensors were fitted by the dealer pre-delivery, and the outer ones are fitted a good deal higher than the middle ones.

[Oldie]

Thanks Downsizer, your layout sounds similar to ozzie with his newer Hybrid.

This link to a Honda brochure shows what I think I want and I saw a Jazz on Saturday, 2009 reg plate with just this arrangement: www.honda.co.uk/cars/_assets/downloads/jazz/Jazz_Accessories_final.pdf

The layout you and ozzie describe is probably needed for some newer models because Honda has changed the shape of the rear bumper. Other than that, I don't know why a particular layout is selected by the dealer.

[chrisc]

Chrisc - well done, it looks very tidy and professional. Do you intend to colour-match the sensors in place or leave them black?

Good luck though if you do decide to have a go.

It is my neighbour's car.  I used a hole cutter and they slipped in easily.  A fairly tight fit and I applied some contact adhesive.  I don't think he plans to paint them.  There is a ridge on the device which I gathered from the atrocious instructions has to be vertical

[Kenneve]

UPDATE:-
Have now had a generic set, which I believe are Valeo, fitted by Avonvale Honda in Solihull, total cost £280.
The car was collected & delivered back, sensors painted to body colour, no visible wiring and generally a fine job.
The position of the sensors is a little different to the dimensions previously described. The inner ones are 480mm centres x 450mm high and the outers are 1390mm centres x 530mm high. They appear to start bleeping at about 1.3 mtr and give a continuous sound at about 280mm
As I said previously, not the cheapest route, but having reached the wrong side of 75 years, I am past crawling about under cars! 
All in all, good job, well satisfied and  my thanks to all members who contributed to this post.
Best regards.

[chrisc]

I was checking out the detection area and shape from the sensors

It appears to be a fat sausage balloon shape and extends to about 4 metres.  It hits the ground about 1/2 metre from the bumper and at 1 metre from the device it is 1.2 metres round.  So there is some overlap from the rear-facing sensors and the ones on the edge detect past the edge of the car.

This causes objects like a raised fire hydrant to be detected, but then you are not supposed to park in front of a fire hydrant, although everybody does and the cops do not bother.

If the sensitivity control is turned up, the range does not alter but even a very small object like a screwdriver will cause it to react.

[Kenneve]

Yes. I have noticed, that when parked alongside other cars in a carpark, the sensors do react to the car next door, which can be little confusing.
There is also quite an overlap between adjacent sensors, which means that there should not be any dead spots at the rear of the car.
Where is the sensitivity control? It would appear that my control box is somewhere behind the boot panels! I haven't found it yet.

[chrisc]

Well, the device I fitted was made in China and had instructions like:  "When led lit out is indicating partially wiring crumped", and, "too fast will consider it to wail as distress", and other helpful sentences

I mean you need an Inglish to English dictionary to figure out what they mean.  There is a controller and inside are two trimmers.  One alters the frequency and the other alters the range.  I figured the range one since it simply reduces the voltage to the transmitter/receiver head.  On maximum it sent 12.4 volts, on minimum it sent 5.5 volts.  I found that just above minimum worked best.

It was made by the Grand March Electronic Works in Shenzhen.  I sent them an email and got a reply in Chinese characters.  I sent it to my Chinese friend and he said the message read something about the model is made of very superior parts.

[Ozzie]

My previous car was an Astra, which I also fitted after-market sensors too. It seemed far too sensitive with the sensors constantly bleeping. I asked the fitter to check it out, and it appeared that one of the sensors was fitted upside down, so that it was constantly picking up the road as a close object, once it was turned round all was fine.