Dear BMW enthusiasts,
I am having a problem with the PDC system of my 530dA euro version.
It has 8 sensors, 4 in the front, 4 in the back.
I trouble shooted the fault and want to share this with you.
The front and rear sensor connector can be swapped if the harness is removed. This way the pdc module can be checked for faults.
- The system works with a self test when turned on through the pdc button or reverse.
- The system beeps for three seconds followed by continues flashing of the pdc LED when one of the sensors is defective
- Three second beep in the front: one of the front sensors faulty. (v.v. for the back)
- Disconnecting connectors on the pdc control module:
- bottom connector=white: rear sensor set: 3 second rear beep follows when activated
- Mid connector=black: power supply, I-bus, speaker connectors etc. Disconnected leaves pdc system always off.
- Top connector=blue: front sensor set: 3 second front beep follows when activated.
I did not try this but I assume the pinout of the front and rear connector is the same
swapping the connectors without change in symptoms would indicate PDC module failure.
Battery negative lead does not need to be loosened when the ignition key is removed. Power to the PDC module is lead when the ignition key is in second position.
- Each sensor has three wires (supply, lead and return) as in normal transistors.
- Specific faults like ground shorts can be found using the I-bus link to the DIS system
- To define which sensor is defective or not connected: listen to each sensor when the pdc system is activated.
- A well functioning sensor is indicated by a "ticking" sound as in static discharge (+/-2Hz)
- Faulty or non connected sensors: 100% quiet.
- All sensors quiet though means loose connector or faulty pdc unit.
The cable loom starts in the trunk: right side just above the battery (my pdc module is white and writes PDC on it).
The cables itself go from there to the front on the right side of the car.
Sensors front and rear are different types and can be indicated by the realoem.com site under electronic distance systems
The sensors seem to have an orientation when mounted. the activation angle is 90 degrees in the horizontal plane and 60 degrees in the vertical plane.
Don't know the orientation w.r.t. the sensor but will just follow the orientation from the other 3.
More detailed info can be found in: e38.org/part2driverinfo.pdf from page 124.
Unfortunately the complete rear bumper needs to be removed to check a loose connector or to replace a sensor.
I am going to use existing threads in this forum to do this.
Regards, Guido Maas
Good info - that listening thing is a good idea.
Yes, it's a 6-speed Touring...
- a pair of early factory Touring tails - the all-red US type
Thanks for sharing.