BMW 5 series e39 2.5 TDS 2002 Tourer - Voltage protection relay 2 #
Posted by Keith Brown on May 22, 2012, 6:44 pm
Year of Manufacture *: 2002 ( Optional ) Engine Code or CC: 2.5 tds
Hi
wonder if anyone could guide me on this one car came in with no indicator & main beam tell telltale,no radio/satnav display, park sensors & reverse lamps six fuse boards on this car, fuses all good global scan would only connect to transmission,no codes ran a can test & first result was short to ground,rechecked & both lines ok! using dec, not scoped yet after looking for main ign relay autodata not that clear but found some in o/s/r boot area, there are four relays 2 light green 5 pin one is voltage protection relay 1 & the other voltage protection 2, soon discovered if this relay is pulled all systems come back on line except the radio & cd,the nav works & its a combind unit the ad wiring diagram for this vehicle is poor to say the least
My understanding of the use of this relay is limited other than its there to protect vital hardware the relay functions fine off the car,its a standard 5 pin ive disconnected the audio unit hoping to see a change in the electrical systems to no avail fuse 43 in glove box serves the relay along with lots of other systems alternator charge rate is good along with batt condition sorry for the long post feel the 2 hours wasted on this car are down to my poor data if someone has a schematic for the rear fuse board/relay plate on this one it would help could someone explain the relays full function it would help greatly one of you guys may of experienced the same issue and could assist on this one
Keith ps: a global scan with the relay disconnected only revealed a coulpe of power supply codes/not present
Re: 5 series e39 tourer voltage protection relay 2?
These symptoms are often due to corrosion on the audio connectors. Unplug the CD changer and recheck, or ipod connector if it's had one installed. I think you're in the right area by focusing on the audio side of it. Also try unplugging the amp if it has a factory fit one (DSP or HiFi).