Hey Y'all,

The wife recently purchased a a 2013 R56 Mini Hard Top with the N16 (Naturally Aspirated) motor, 84k miles. Very clean car and well maintained but she hadn't put 300 miles on before it stalled at a red light. I've done quite a bit of reading on this topic and noticed it's been quite common. So I'm getting 10.8v at the pump when car cranks and runs for approximately 4-5 minutes then stalls and I goes to 0v. Car will run for a bit then stall and not start, if you wait 10 to 15 minutes it will start and run then stall again. Thought it was the relay (JBC) down on passenger side foot well myself and was going to repair but the wife insisted on taking it to the dealership. I tried convincing her and warned her not to do it but of course she's stubborn and did it anyway. Dealership calls and says yes, it's a bad relay and she had the replace the whole fuse panel (JBC) which came to $1200. Next day the dealership calls again and says the relay didn't work and now you need a new ECU/DME. Now mind you she received a video of said mechanic going over the car etc and states that the JBC relay was bad and needed to be replaced along with a new water pump and the cost of the job then the video ends. Never saw them scan the car, she received no codes nor proof they ever scanned the car, so my question is how the hell did they come to the conclusion the (JBC)relay was bad in the first place and then say the ECU/DME are bad? They charged her $1200 and had the car flat bedded back to the house. I'm getting 47-48psi at the fuel rail, I've read conflicting reports stating it should be around 72psi others say 50psi as I thought maybe a bad fuel pressure regulator. Thought that I'd maybe get lucky and not have to purchase a scanner but it's not looking promising. At least now I'll have a fuel pressure gauge and scan tool for future issues 😂.
​Anyone have any idea or direction on what to do or where to look? I did also just found there's another relay under the hood next to the DME that could possibly be bad but to me if it was bad the car wouldn't start period. Would you have other issues if it were a bad ECU/DME? Really appreciate some help

 

Relays often fail intermittently. You could try tapping on said relay to see if the car will start sooner than 10-15 minutes after stalling.

Your dealership experience was an unfortunate nightmare.

 

Appreciate the info! There's a relay under the hood next to the DME that may be faulty, I wasn't positive if a relay could work intermittently like you stated. Definitely makes sense from symptoms, hopefully that's the culprit

 

Let's start with your comments:

1. So I'm getting 10.8v at the pump when car cranks and runs for approximately 4-5 minutes then stalls and I goes to 0v.

All of this sounds normal; when your starting the engine, there's going to be a voltage drop since the starter motor is consuming a huge amount of current. The fuel pump will only run for a short period of time unless the engine starts successfully. If the engine doesn't start, the DME cuts the power to the fuel pump relay until another start is attempted.

2. "Car will run for a bit then stall and not start, if you wait 10 to 15 minutes it will start and run then stall again." This could be caused by many things. So, I'd start by ruling things out. Connect your fuel pressure gauge to the fuel rail, and attempt to duplicate the stalling problem; watch the fuel gauge to see if the fuel pressure drops when the stalling occurs. If it does, that will point you in the direction of the fuel system. You can also connect a scan tool under OBDII protocol and monitor your short term and long term fuel trims. + numbers mean the engine is running lean (can cause the engine to stall), and the DME is calling for more (+) fuel. Negative numbers mean the engine is running rich, and the DME is calling to subtract fuel. You want to see your fuel trim between -10 and +10; a perfectly running engine will be at zero.

2.1. The loss of your 5 volt reference circuit could also be causing the problem. You'll need a diagnostic guy with a lab scope to connect to your 5 volt reference circuit and attempt to duplicate the stalling problem; based on your description, I doubt this is the problem, because "normally" a problem with the 5 volt reference circuit (shorted hi or shorted low) would set a diagnostic trouble code (DTC).

3. "Thought it was the relay (JBC) down on passenger side foot well myself." According to Mitchell1; there is only one relay between the DME and the fuel pump, but you do not have to replace the whole fuse panel to change the relay. Item 2 in the picture below is the fuel pump relay, and it's not soldered to the board like some BMW/MINI relays are. Whenever you take your car in for repairs, make sure you always request the old parts. This way you'll know what's been replaced, and you can ask more questions like "Which one is the fuel pump relay?"



Here's the schematic. Pin 17 is the signal from the DME to energize the fuel pump relay.



If you think you are losing power to the fuel pump, that will show up when you connect the fuel pressure gauge. If the pressure drops when the car is stalling out, you have to determine if the fuel pump is getting power or if the there is another problem like a faulty fuel pressure regulator. The easiest way to check the power side is to connect an amp probe to the white/blue wire that's going from the relay to the pump. If you are losing power, you'll see it. It's also possible that the fuel pressure regulator is dumping too much fuel back to the tank. Again, it that's happening, you'll see it on your fuel pressure gauge.

4. "it's a bad relay and she had the replace the whole fuse panel (JBC) which came to $1200." Sounds like total BS to me. See pics above. Again, ask to see the parts that were removed.

5. "Next day the dealership calls again and says the relay didn't work and now you need a new ECU/DME." Sounds like the dealer tech needs to go back to school. Since the DME controls the fuel pump relay, it would be very easy to determine if the relay is getting power from the DME, or if the relay is being energized but there is no output power to the fuel pump. Basic tech stuff.

Now on to my personal 2013 MINI (N16); it belongs to my sister-in-law. She recently called because her car was shuddering at idle, and the check engine light was on. I connected a scan tool, and found a P2187 "lean at idle" DTC. I pulled up fuel trims and noticed very high positive numbers (+30) at idle, but the faster I drove the car the more the numbers returned to normal. MAF was at 1.8 grams/sec, so I pulled the MAF and cleaned the sensor); that didn't help. I replace the MAF, and the grams per second at idle went up to 3.6, but the car was still shuddering at idle and the idle fuel trims were still way to high. So, I pulled up the upstream O2 sensor current, and introduced propane to the intake. There was no response from the upstream sensor, but the downstream sensor went full rich. This told me the upstream sensor was faulty. OBTW, there's no DTC for a faulty O2 sensor in memory. You may have a similar problem.

Do not let the stealership replace your DME! There is a place you can send your DME for testing; last time I used that service the cost was $150.00 to test the DME; you have to send in your DME, CAS module, and key. They will plug your components into one of their cars for testing. The service was excellent!

Post review edit. Do you see the terminal 30 G relay at the top of the schematic? That relay is soldered to the JBE motherboard; if it fails, you do have to replace the whole board because dealer techs don't repair boards; they swap them out. So, if you insert the key, and press the start button to power up the car, there should be system voltage on that relay terminal coming into the fuel pump relay. This is a ground-side switched circuit meaning the DME provides the ground for the circuit to operate. So, there could be one of two problems on this part of the circuit. Either the driver in the DME is not providing the ground (easy to check), or the terminal 30g relay is not providing power (also easy to check). It sounds like the dealer tech guessed and assumed it was the terminal 30g relay without performing basic tests, replaced the JBE (and the soldered in term 30g relay), and then when that didn't fix it, he's assuming the DME is not providing the ground. Still, we don't actually, know if the fuel pump is losing power or not.

 

You may have already seen these three videos during your research of the stalling problem.

I know the dealership told you that they replaced the JBE, but because they don't seem reliable, you may need to repeat the JBE diagnostics yourself.

If the JBE relay is indeed bad, it can be purchased for about $8. See next video for how to do the repair.

This guy's JBE relay was good but had a bad solder joint.

This guy's stalling problem was interestingly a loose ground wire on the valve cover.

 

That valve cover ground is for the ignition coils.