Hello.
My wife bought this 325 convertible and each time we put it in reverse, it beeps a long beep and then go silent afterwards.
I have figured out the long beep is to inform that something is failing.
Bought a Foxwell NT520 tool to diagnose the PDC, but it doesn't record any error codes and there is no "clicking" sounds from the sensors.
I have checked the fuses, that i think of (fuse 24) and it is not burned.
Live data is showing that all sensors are equaly tuned, which i guess that there is no communication with the sensors/computer box.
Any ideas on where to start troubleshooting? Kind of suspect that it might be the main computer box for the pdc, but before i start buying stuff, i would like to hear others experience of what might be the problem.
Greatfull for any advises on how to proceed. Can it be some cable that is broken, and which one??
The problem with PDC sensors is that they tell lies. Even if they click, they may still not be working properly. And if one fails, it takes the others with it and the system goes down. I have over a dozen brand new aftermarket sensors and they are all junk. So I would suggest only fitting OE sensors. Yes, they are expensive so borrow some if you can and see what your diagnostic tool makes of them. I use DIS which is able to tell me how far an object is from the car. It is a big hint if a supposedly working sensor displays 2.5m (which I think is the limit of the range) when I am standing right in front of it. Hopefully, your kit will do the same. BTW, I replaced the control unit and loom before I concluded that sensors lie.
The aftermarket PDC diagnosis tool you bought may not work on the E46. Best bet is to get a laptop with INPA and BMW OBD-cable (i.e. from cable shack) and check the PDC with that. It's probably cheaper than the aftermarket diag tool and will also help you a lot in the future
Thanks for the feedback.
All 4 sensors are saying that it is 2,5m clearance. Even after the long beep. No error code is registered.
Thanks for the advice regarding the INPA, will look into that. I primarly wanted an easy to bring around unit in the garage, and this aftermarket reader was "best in class" for the money..
Will try to collect some extra sensors and try to switch them.
Can you measure the sensors somehow??
The control unit is behind the right-hand panel in the trunk. The loom runs from that to the sensors. You might not find it in realoem but your friendly BMW dealer can order it. I would not consider changing it for now though. I found no way of bench testing sensors. I put a chair in front of each sensor and check to see if the distance from the sensor is correct. If it stays at 2.5m, it is likely to be faulty.
It might seem a bit odd that the whole system stops working if you have only one faulty sensor. Of course, Murphy's Law states that it is the part of the car where the sensor does not work which would collide with a concrete post. So I prefer that it works like that - perfectly or not at all
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