Complaint car would not lock or unlock on key fob. central locking working normall on all doors and the mechanical key, but if car was locked with the key it would sometimes unlock using the fob .......
LED signal indicator was lighting on both keys but being a parts changer I renewed the battery in both keys, no change, however before going further spotted Chinese made aftermarket wireless parking sensors on the front .
I unplugged the the parking sensor reciever unit (powered from the cigar lighter socket) no change.
Disconnecting the power to the transmitter unit under the hood that and the locks worked perfectly --- parking sensor was jamming the key fob's radio frequency.
The tramsmitter should be powered from a supply that is only live key on so I checked the power to the transmitter unit which was under the hood and found no 12v power to the transmitter and found zero volts with the ignition off, but tested again sometimes it had 12v wtf
Eventually the penny dropped it was powered by a fuse controlled by the BCU which remained live for 120 seconds after key off.
So I wired the transmitter to a 12v supply from the main relay and used an in-line fuse and the central locking and **** parking sensors both work how legal they are radio interference wise is not my concern.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Last edit: 6 years 5 months ago by Andy.MacFadyen.
The majority of cars here only got them in the last 5 years. I fitted a few high quality Veba systems to vans a few years back. Now the cheaper Chinese ultra systems are retailing for about £12/14$/13 Euro and they work quite reliably.
The factory fit system on early 200s BMW & Range Rover & MG-Rover were pretty unreliable and altough on the K diagnostic bus they were a pain to fault find I discovered that the cheap kits can be fitted in place of the BMW sensors and the beeper just fitted on the rear.
Only real fault with the cheaper systems is supply wires aren't realy up to automotive standards but I cut and splice the wire to heavier gauge close to the module
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
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