E46 Parking Sensors - not your usual problem
Discussion
Ok so I know there's a gazillion threads on E46 parking sensor issues, however this one is different to the usual 'check which sensor is not clicking and replace it' thread.
When I start the car in the morning, the rear PDC works perfectly. No problems whatsoever. However when I arrive at work (only 6 miles later), upon selecting reverse it will beep rapidly for 2 or 3 beeps, then go to a consistent tone the same as when you're very close to an object. I've gotten out of the car and checked all 4 sensors, and they're all merrily clicking away.
If I turn the car off and leave it, even for only 5 minutes, then start her up again and try again, they work perfectly. I thought it may be a heat soak issue, however they were working ok in the summer when the ambient was easily 20C warmer than current.
Any ideas? Has anyone else experienced this exact same issue?
When I start the car in the morning, the rear PDC works perfectly. No problems whatsoever. However when I arrive at work (only 6 miles later), upon selecting reverse it will beep rapidly for 2 or 3 beeps, then go to a consistent tone the same as when you're very close to an object. I've gotten out of the car and checked all 4 sensors, and they're all merrily clicking away.
If I turn the car off and leave it, even for only 5 minutes, then start her up again and try again, they work perfectly. I thought it may be a heat soak issue, however they were working ok in the summer when the ambient was easily 20C warmer than current.
Any ideas? Has anyone else experienced this exact same issue?
Hello,
I had a spell of a few weeks last year where sporadic problems occurred much like yourself after certain journeys.
The faults would not always manifest themselves the same way either.
In the end I disconnected the battery/ disconnected the PDC unit (accessible from the boot if Coupe (dont know about saloon)and went on holiday for a week.
Upon my return, reconnected and all has been well since.
I was never going to spend money resolving the issue, especially as all sensors were 'clicking' so I knew it would be something more involved/expensive.
If they play up again i'll disconnect probably, and live without them.
Worth a shot I guess....
I had a spell of a few weeks last year where sporadic problems occurred much like yourself after certain journeys.
The faults would not always manifest themselves the same way either.
In the end I disconnected the battery/ disconnected the PDC unit (accessible from the boot if Coupe (dont know about saloon)and went on holiday for a week.
Upon my return, reconnected and all has been well since.
I was never going to spend money resolving the issue, especially as all sensors were 'clicking' so I knew it would be something more involved/expensive.
If they play up again i'll disconnect probably, and live without them.
Worth a shot I guess....
I had a problem with my E46 parking sensors intermittently giving a constant beep despite there being nothing within range. evenutally i found a spider living in the black fake grille type thing where sensors are mounted. After evicting him the problem went away! it's not always a mechanical/electric problem!!
Same problem with mine. Put up with it a while, when the car was in for something else I had the PDC diagnosed and it was showing that one of the sensors was detecting an object that wasn't there. No fault codes showing.
Bought a new sensor but not got around to fitting it. The other day for the first time I got the 4 second beep and flashing PDC light that indicates a fault - it now shows a fault code on the same sensor.
It's probably just a sensor, like mine is.
Bought a new sensor but not got around to fitting it. The other day for the first time I got the 4 second beep and flashing PDC light that indicates a fault - it now shows a fault code on the same sensor.
It's probably just a sensor, like mine is.
Thanks Fox - I guess it's just trying to find which damn sensor!
As an update, I've been trying all sorts of things to see if I can make the fault repeatable, but to no avail. The one thing it always does it work ok from cold 100% everytime. However when the car's warm, most of the time it goes into the constant tone routine, however there have been the odd times when it's been ok.
I've also tried cleaning the sensors when they're playing up, then immediately trying it again and the results are again variable.
I guess I'll just have to have the rear trim off (saloon), check the wiring and if that fails, to find anything, buy a single replacement sensor and start trial and error of placing it in each of the 4 available channels and seeing what difference it makes.
BMW electrics...Grrrrrrr
As an update, I've been trying all sorts of things to see if I can make the fault repeatable, but to no avail. The one thing it always does it work ok from cold 100% everytime. However when the car's warm, most of the time it goes into the constant tone routine, however there have been the odd times when it's been ok.
I've also tried cleaning the sensors when they're playing up, then immediately trying it again and the results are again variable.
I guess I'll just have to have the rear trim off (saloon), check the wiring and if that fails, to find anything, buy a single replacement sensor and start trial and error of placing it in each of the 4 available channels and seeing what difference it makes.
BMW electrics...Grrrrrrr
The better diagnostic systems allow you to see the data from the sensors - ie, how close objects are. You can also do this yourself if you have an Intravee and Nav, IIRC.
From here its easy to see which one is giving false positives.
There are few if any expensive parts in the PDC system. I had the main control unit go once - 25 quid..
From here its easy to see which one is giving false positives.
There are few if any expensive parts in the PDC system. I had the main control unit go once - 25 quid..
Ok update on this.
In spite of all my 4 sensors clicking away, yet still getting the constant tone from the PDC, I've taken the step to replace all 4 sensors.
Rather than blowing circa £400 on BMW parts, I purchased 4 x brand new LR Discovery sensors for 33% of the cost (as per the thread here). The parts themselves are almost identical, and both are made by Valeo.
So I replaced them on Saturday, and have been driving every day since. And, fingers crossed and touch wood etc, they've been working perfectly ever since. I've even jet washed the car to see if I could get them to 'fail', but they've worked perfectly each and every time. So far, I'm a happy chappy! I will update this thread again if anything changes.
Cheers.
In spite of all my 4 sensors clicking away, yet still getting the constant tone from the PDC, I've taken the step to replace all 4 sensors.
Rather than blowing circa £400 on BMW parts, I purchased 4 x brand new LR Discovery sensors for 33% of the cost (as per the thread here). The parts themselves are almost identical, and both are made by Valeo.
So I replaced them on Saturday, and have been driving every day since. And, fingers crossed and touch wood etc, they've been working perfectly ever since. I've even jet washed the car to see if I could get them to 'fail', but they've worked perfectly each and every time. So far, I'm a happy chappy! I will update this thread again if anything changes.
Cheers.
Hi there
Have similar issue.
Had a friend with INPA and did a check on the rear parking sensors and result was mid right centre rear open circuit (e46 318ti 2002). Bought one off eBay after market and the 5-10 consistent peep no gone but it seems its picking up something when nothing there.
Any ideas? When placing hand over each one, they pick up but new one when completed covered stops bleeping. Same for another original one.
Any ideas would be much appreciated.
Regards
Nick
Have similar issue.
Had a friend with INPA and did a check on the rear parking sensors and result was mid right centre rear open circuit (e46 318ti 2002). Bought one off eBay after market and the 5-10 consistent peep no gone but it seems its picking up something when nothing there.
Any ideas? When placing hand over each one, they pick up but new one when completed covered stops bleeping. Same for another original one.
Any ideas would be much appreciated.
Regards
Nick
Totally agree to buy used E46 parking sensors that are in tested/working condtion instead of new 3rd party.
I fixed the 'long beep' E46 parking sensor problem on my 2001 E46 by:
1. Unclipping the plastic strip where the sensors are placed, using a flat head screwdriver as leverage to pop it out [easy does it]
2. Unclip and push the old sensor out
3. Buying a used/tested parking sensor on eBay like this one [check the part number on your existing one obviously]
4. Simply plug in and rejoice in the sound of your functioning E46 parking sensors
Took me about 5 mins and cost £10.
I fixed the 'long beep' E46 parking sensor problem on my 2001 E46 by:
1. Unclipping the plastic strip where the sensors are placed, using a flat head screwdriver as leverage to pop it out [easy does it]
2. Unclip and push the old sensor out
3. Buying a used/tested parking sensor on eBay like this one [check the part number on your existing one obviously]
4. Simply plug in and rejoice in the sound of your functioning E46 parking sensors
Took me about 5 mins and cost £10.
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