Reading on the forums most people said the fuel pump was dead. I removed the fuel pump as stated at North American Motoring and inspected it to see what broke. Hooking it up directly to 12V, I noticed it actually ran just fine!!!
Next, I tested the power going to the fuel pump via the connector. Putting my meter between pin 2 and pin 5, (Pin 2 (Blue/White) is +, Pin 5 – (Brown)), I got 12v when the car was switched on. That appeared to work, so I was wondering what was going on? The fuel pump appears fine and the power going to it is working too. I reinstalled the fuel pump and hooked some test leads between the connector and the fuel pump so I could measure current and voltage. I notice when the car turned on, it was not supplying any current to the pump. Basically the meter was measuring 0v when it should be measuring 12V. This lead me to believe that the control signal was somehow directly tied to the fuel pump, vs. the control signal turning on the relay to the 12V supply. Pulling the fuel pump fuse also did not stop the 12V signal from coming on when the car was turned on and the cable was disconnected from the fuel pump. This further lead me to believe the relay was dead.
So where is the fuel pump relay on this mini cooper? Believe it or not, after hours and hours of searching I found it. The relay is now part of the interior fuse panel. If your MCS is experiencing this issue you can either replace the whole fuse panel or put a generic relay in its place. I chose the latter.
(Relay is solder to the board located under the plastic labeled RL1)
To replace the fuse panel on this car, you need to remove the rear seat, rear drive side seat back, rear driver side panel and then the driver side kick panel. 2 x 10mm bolts hold on the fuse panel and then a number of cables connect to in on the back. I took a picture with my phone before I unplugged these connectors to ensure I plugged them back in correctly.
The fuse panel connections are actually color coded with the lack of color equating to black. It's probably not a bad idea to disconnect the battery before unplugging these connectors ;-).
Once you have the fuse panel off, you now need to remove all the fuses. I again took a picture before I did this step (see above if you don't). This made it super easy to re-install them when it became time.
Next, the two halves of the fuse panel snap apart if you use two flat heads to pop the two sides up. It's fairly easy. Now the fuse panel circuit boards will slide out and you will notice how they are attached to each other
Unfortunately to do this repair the “right” way you would need to de-solder each junction, pop apart the boards and then re-attach. I chose to do it a different way. You will notice that this relay is totally smoked in the below picture.
Digi-key, mouser and newark where all out of stock, so I just bought a 30Amp relay from radio shack and hardwired it on. To do this I just snipped off the relay and ohm'd out the connections to the interconnects.
Here is how I wired the Tyco V23086 to the Radio shack SPST relay:
Tyco - Radio Shack Relay - Usage (Color and Pin on White connector)
1 - 86 - Positive Control Line (Red/Black 5)
2 - 85 - Ground control line (Black/Violet 6)
3 - -- - No Connect
4 - 87 - To F37 fuse (12V internally connected to fuse)
5 - 30 - To fuel pump (Blue/White 3)
(You can also snip these connections and run a dedicated fuse/relay pair directly from 12v)
I drilled a hole through the back of the panel, fished the wires and soldered the leads onto the board interconnects. On the exterior of the fuse panel, I crimped some female spade connectors and hooked it up to the relay. After that, the boards where reinstalled into the housing, snapped back together and the fuses were replaced. The assembly was then installed back into the car, and all the connectors re-seated. Testing, the fuel pump went on when the key was turned and worked when the car was started!!!
I zipped tied the new relay up to the car and reinstalled all the panels and seats. All works fine now!
UPDATE:
I found a source of the actual relay. If you can wait for one and want to make sure no one is the wiser if you ever get your car repaired (which happened to my girlfriend later on). Use this source
I would dead bug it on the board with some crazy glue and then glue the wires to it. Hopefully people will not charge you (or your friend in my case) hours of time searching for an alarm system that does not exist.
If you have this issue, you should also expect that your BCM is about to die. The fuel pump tied to the BCM directly is too much current for the STMicroelectronics controller and I believe ends up frying it. If this happens to you too in the near future check outhow to fix a BMW BC1 Cheaply.
In conclusion here is what I would do if it happened again to diagnosis a mini-cooper fuel pump issue.
- Ensure Fuse F37 is not blown
- Remove the rear-seat, unbolt the protective fuel pump cover (driver side), unhook the connector and apply 12v to the blue lead location and ground to the brown lead location. See if the pump works. (run a line from your trunk battery)
- If it works replace or fix the fuse panel. If it doesn't replace the fuel pump.
Hope this helps!
-Trunk
