Front sensors sensing!

[lex3]

Hi,

My is300h Premier with factory fitted parking sensors has started sensing nothing! When I come to a halt the parking display shows a red bar at the front of the car and the beeper sounds continually. When I drive off and reach approx 7-10mph the beeper stops and the display goes to normal. If I drive close to the wall at my side the sensors pick that up and show the 3 orange bar symbol gradually going to 1 bar and then red but there is this red bar along the front even when there is nothing in front. There is no sign of damage, I've cleaned the 2 sensors in the grill and the left and right hand side senors but just the same annoying red line and noise.
I know I can turn it off but I usually drive with it on - as I do with all my in-car labour saving devices!! 

Anyone any ideas - thanks.

Ian j

[ColinBarber]

It sounds like a sensor failure. Try and make sure nothing is in the gap between centre part and outside. Run a piece of paper around the gap or try and clean with a fine bristle toothbrush.

[Carl1983]

I own a Lexus IS and we also have the new Toyota avensis. this same thing happened to our avensis last month and it turned out to be a faulty sensor. it was all sorted and replaced under warranty. if you have warranty is go and get it checked out 

[rayaans]

Yep sounds like a faulty sensor. 

Typically its the 2 central ones. Quite rare mind but I doubt its anything else.

[darrude]

mine does this occasionally, at the start of a journey, but then seems to fix itself.  Seems worse in cold weather.  I've wondered if it's when its particularly dirty.  Is your's doing it Persistently? 

[lex3]

On Monday it was very intermittent, Tuesday and Wednesday it was constant once speed dropped to below 8mph with totally clear in front. Corner sensors would pick up and flash orange bars down to red on driving close to walls etc, but the red bar across the front without the warning bars. I did think it was a solid red, but today it is more a red/white striped bar (like warning tape).

I did clean the sensors as advised, maybe that's why today has been different but I don't think I can get them any cleaner - it's not that after cleaning they worked properly, just not constantly, which makes me think the sensors haven't failed!

Guess maybe its a visit to the dealer!

Thanks for the help and advice - I will try a clean again on Thursday - and any other recommendations.

ian j

[darrude]

sounds like a failure, pretty sure mine is just muck, not done it recently, but It has had it's fist clean in about 9 months...

 

I think the different colours might be down to which screen you look at, the one between the dial uses a different colour scheme to the centre screen.  I don't think the engineers were talking to each other when coming up with the graphics for each.......!

[wharfhouse]

Had this happen to me for the first time today. Sat at traffic lights and was at the front of the queue so nothing in front of me. Pouring down with rain and suddenly the front parking sensors (centre ones) went off much to my amazement and that of my passenger - just as if I was approaching a wall! As soon as I set off they stopped and didn't have the problem from there on. I put it down to rain running down over the sensors. 

[wakhtar]

I had this happening with the snow we had recently and then again with freezing overnight temperatures, I assumed it was ice that had formed, seemed to sort itself out after a few hours

[DanD]

I had issues with parking sensors a few years ago on an RX. It was explained to me that the sensors are made of three main parts. An outer ring, a small disc (the sensor), and in between a rubber ring. The sensor works in a way similar to a sonar, sending and receiving sound waves. The rubber ring around it allows the sensor to register the tiny vibrations from incoming sound waves.

In my case, 3g clear coat had been applied to the car, including the sensors. Over time, the clear coat had hardened to such an extent, and the rubber rings with it, that the sensors no longer worked properly. Dealer took them apart, cleaned them, and refitted them. Did not have any issues after that.

I guess that, on this basis, hardened dirt or ice could also interfere with the sensors.

Sent from my LG-H930 using Tapatalk

[lex3]

That sounds very similar to my problem with my sensors. I haven't reported back yet as almost every time i go out in the car I get a different scenario. Gave them a good clean, working properly for trip of 8 miles, return journey sensors sounding with nothing in front. Next day outward trip they were sounding with nothing in front for first couple of stops, then started intermittent, by end of 22 miles they were operating properly! Just find it hard to accept they are faulty when they work perfectly sometimes, thinking it could be weather related and as Daniel mentioned the clear coat hardening.

Another good clean needed - and better weather!! - I think before dealership.

 

[NemesisUK]

Could it be wet/damp getting into the connections on the rear of the sensors?

[lex3]

So finally gave in and asked the dealership to check my sensors. Result was a faulty sensor on the front drivers side (in the grille). Replaced and all OK now. Thanks for the suggestions.

[sheamus]

Ian, how much did that cost?

[lex3]

£83.36 for parking sensor, £110.00 for strip down, rebuild and test, plus VAT £38.67  :   Total  £232.03 
I also had 2 lattes and 2 Tunnocks Caramel Wafers - these were FREE!!

[matt8]

Free, or paid for in the cost of the sensor job?