Hello everyone,
I just recently bought my 02 r53 last week and have some issues. My left rear tail light and left front parking light don't turn on only the right ones turn on. I have tried changing the bulbs and fuses but still no luck. I also switched the read black board that holds the bulbs on the tail light and they work fine on the right side. I've also done a ecu reset and still no luck. What other options do I have thanks.

 

Isolate the fault.

With a multimeter, check voltage at fuse box, do you have power going into and through the fuse? Yes - Is the fault in the wiring? Check the continuity between wiring segments. e.g., from the bulb to the fuse box.
If No power at the fuse box, chase the circuit back to the ECU. Also check for evidence of damage done to wire looms possibly done by wild life (critters nibbling on wiring).

Electrical Diagnostics is a time consuming task, and if you decide to take it to the shop you can pay for LOTS of hours as the Techs trace the wiring. The more you can do the least expensive it will be for you.

I have also seen results after resetting the ECU connector, (disconnect battery, disconnect ECU connector, spray contacts with "Electrical Contact Cleaner" both at the ECU and the Wiring harness connectors, reconnect ECU, reconnect battery)

Also see if the light illuminates when pressing on the brake.

Best of luck.

Motor on!

 

99% chance the bcm is fried....
The body control module....
Think of it as a tiny computer and amplifier most modern cars use to convert signals from a computer signal to a light turning on....modern cars do not use relays and switches, but you flip on off switches...which send a signal to the bcm to turn the light on....
Since different things can turn on lights...different switches, the airbag module once deployed, or the alarm system, it reduces the spegetti wiring found in many slightly older designs.....
Do check for the right bulbs, ground and wiring issues....but bet the bcm, located by the passenger side foot well, inside is wet, or has been shorted by a wiring issue(double rear brake lights with a common jumper is often the cause, where the unused rear fogs are wired wrong to makes brighter tails)......the bcm is basicly overloaded, and fails....in the rear foglight mod some current can back feed up unused wires and fry it coupled with an overload situation....

 

thanks guys will try this out to see if it works.

 

I have a very similar problem my I have a 2005 Mini Cooper conv, both rear brake lights aren't working, none of my passenger side indicators work and neither does my front driver side low beam. The indicator flasher in dash works normal though and doesn't flash quick like I'd expect it too? Any ideas any one???