Reversing Sensors.... Useless - Be Warned! - Page 3 - BMW 3-Series Forum (F30 / F32)

Spacebug · 01-08-2013, 03:54 AM

Quote:

Originally Posted by zofinger

Couple of thoughts 1) if it helps you can adjust the volume of the PDCs so they're not quite so 'overbearing' and 2) this if the first time i've had PDC's so have no experience to lean on, but the manual does note the sensors functionality could be impacted if they are dirty? Wonder if this was part blame for not seeing that huge post...

I think you may be on to something! As you can see from the pictures, my car was pretty dirty.

It could also be a factor in why the front sensors work better than the rears...

I should

RobUK · 01-08-2013, 04:39 AM

My rear sensors 'dance' when they're spotlessly clean

rich1068 · 01-08-2013, 07:38 AM

Slightly off topic but I find the front sensors very handy. I don't know what is with this car but I find the front very difficult to judge. Without the sensors I think I'm right up against something and I'm miles off.

zofinger · 01-08-2013, 09:43 AM

Quote:

Originally Posted by rich1068

Slightly off topic but I find the front sensors very handy. I don't know what is with this car but I find the front very difficult to judge. Without the sensors I think I'm right up against something and I'm miles off.

Agreed - only done 800 miles so it's all still new to me but the front feels closer to the obstacle than it actually is.

Spacebug · 01-09-2013, 06:59 AM

Quote:

Originally Posted by zofinger

Agreed - only done 800 miles so it's all still new to me but the front feels closer to the obstacle than it actually is.

Yep me too... Usually very good at judging distances etc..

Signpost · 01-10-2013, 09:39 AM

Having looked at the photograph of the offending wooden post and the advice contained on Page 118 of the Owner`s Handbook, warning of the limits of ultrasound measurement, including a thin or wedge shaped objects, the following thought may be relevant.

Could it be that almost all of the Ultrasound beam was reflected away from and not received back by the relevant sensor, due to the shape of the post. That would mean that on its own, the thin leading edge of the post was borderline in respect of the signal strength received back by the sensor.

I am not sure how Ultrasound works compared with Radar but assuming similarites, military Stealth Aircraft and Ships produce a very small radar return, partly based on the the special angled shape of the bodywork. This may or may not help to support the above theory.

Standing by to be shot down by experts!!

rich1068 · 01-10-2013, 10:07 AM

You sound like you know what you're talking about. That's good enough for me!

Spacebug · 01-10-2013, 10:27 AM

Quote:

Originally Posted by Signpost

Having looked at the photograph of the offending wooden post and the advice contained on Page 118 of the Owner`s Handbook, warning of the limits of ultrasound measurement, including a thin or wedge shaped objects, the following thought may be relevant.

Could it be that almost all of the Ultrasound beam was reflected away from and not received back by the relevant sensor, due to the shape of the post. That would mean that on its own, the thin leading edge of the post was borderline in respect of the signal strength received back by the sensor.

I am not sure how Ultrasound works compared with Radar but assuming similarites, military Stealth Aircraft and Ships produce a very small radar return, partly based on the the special angled shape of the bodywork. This may or may not help to support the above theory.

Standing by to be shot down by experts!!

Ah 'Stealth Post fools BMW Technology'... I think you may be on to something! Good analysis!

Quote:

Originally Posted by Signpost

Standing by to be shot down by experts!!

You'll be OK if you hide behind a post..

RamboGrambo · 02-03-2013, 01:14 PM

I added the rear camera, for a little extra reassurance.

Redbaron1973 · 02-03-2013, 06:32 PM

The sensors on my F30 hire car are ok.. seem reasonably accurate.

claykin · 02-03-2013, 07:17 PM

Quote:

Originally Posted by RamboGrambo

I added the rear camera, for a little extra reassurance.

"added" as in retrofit? Do tell us more, please.

RobUK · 02-04-2013, 02:56 AM

Quote:

Originally Posted by claykin

"added" as in retrofit? Do tell us more, please.

Here's one option - http://www.bimmer-tech.net/shop/bmw-...sist-retrofits

RamboGrambo · 02-04-2013, 02:59 AM

Quote:

Originally Posted by claykin

"added" as in retrofit? Do tell us more, please.

Sorry it was a factory fitted option.

Sweeper · 02-04-2013, 02:05 PM

Just a note. Its sometimes 0C sometime -10C and rear sensors are acting damn strange . Even with clean car , with no ice or snow or dirt on them. Sometimes 1 or all together show full coverage (as something is fully in contact)

Damn bmw

01-08-2013, 04:39 AM	#46
RobUK Captain Drives: F30 328i Lux' 8SAT, Red Join Date: Jun 2012 Location: Sussex, UK Posts: 825 iTrader: (0) Garage List 2001 Yamaha FZS1000 [0.00] 2012 BMW 328i [5.00]	My rear sensors 'dance' when they're spotlessly clean __________________ 2012 F30 328i Lux', 8SAT, Melbourne Red

02-03-2013, 06:32 PM	#54
Redbaron1973 Private Drives: F30 320D //M Sport Join Date: Sep 2011 Location: UK Posts: 75 iTrader: (0)	The sensors on my F30 hire car are ok.. seem reasonably accurate. __________________ ________________________________________________ 320D //M-Sport Estoril Blue II with Coral Red ACTIVE CRUISE / ADAPTIVE M SPTS SUSP / HFS / HSWL / HBA / SUN PROTECTION GLASS /INTERNET ACCESS /MOBILE APP PREP /SPD LIMIT DISPLAY / SPRTS GRBX+PADDLES / MEDIA PRO

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01-08-2013, 07:38 AM	#47
rich1068 Colonel Drives: F30 330d M Sport Join Date: Oct 2010 Location: UK Posts: 2,808 iTrader: (0)	Slightly off topic but I find the front sensors very handy. I don't know what is with this car but I find the front very difficult to judge. Without the sensors I think I'm right up against something and I'm miles off.

01-10-2013, 09:39 AM	#50
Signpost New Member Drives: E39 BMW 523iSE Join Date: Jan 2012 Location: Hampshire Posts: 5 iTrader: (0)	Having looked at the photograph of the offending wooden post and the advice contained on Page 118 of the Owner`s Handbook, warning of the limits of ultrasound measurement, including a thin or wedge shaped objects, the following thought may be relevant. Could it be that almost all of the Ultrasound beam was reflected away from and not received back by the relevant sensor, due to the shape of the post. That would mean that on its own, the thin leading edge of the post was borderline in respect of the signal strength received back by the sensor. I am not sure how Ultrasound works compared with Radar but assuming similarites, military Stealth Aircraft and Ships produce a very small radar return, partly based on the the special angled shape of the bodywork. This may or may not help to support the above theory. Standing by to be shot down by experts!!

01-10-2013, 10:07 AM	#51
rich1068 Colonel Drives: F30 330d M Sport Join Date: Oct 2010 Location: UK Posts: 2,808 iTrader: (0)	You sound like you know what you're talking about. That's good enough for me!

02-03-2013, 01:14 PM	#53
RamboGrambo New Member Drives: 2012 F30 320i xDrive M Sport Join Date: Feb 2013 Location: Newcastle Posts: 12 iTrader: (0)	I added the rear camera, for a little extra reassurance.

02-04-2013, 02:05 PM	#58
Sweeper Private First Class Drives: X5 E70 , X5 E53 , R8 , F30 M Join Date: Feb 2010 Location: Europe Posts: 177 iTrader: (0)	Just a note. Its sometimes 0C sometime -10C and rear sensors are acting damn strange . Even with clean car , with no ice or snow or dirt on them. Sometimes 1 or all together show full coverage (as something is fully in contact) Damn bmw