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I believe I found the right one this time with 3 wires (see pictures). Disconnected the fuel sensor and the MAF sensor. Engine cranked but did not start. Got some weird codes on scanner. Fuel pressure sensor code would come on and off. I would clear codes and see some different ones return including MAF and fuel rail pressure sensor. I’m hoping I disconnected the right sensor this time and it was the fuel rail sensor. It was driver side under the coolant tank. I looked at what the sensor looks like if purchased new, and that sensor with power attached looked like the same part. I tried Googling location, but couldn’t find an exact match for 2012 Mini Cooper.
Ugh. A light bulb went off as I was typing last message and my brain just thought to look up the refrigerant pressure sensor. It almost looks like the same shape as the fuel pressure sensor. I’m assuming g that’s why I’m now getting a refrigerant low pressure code on the scanner. Back to searching for the fuel rail sensor. 🤦🏻♂️
Ok. So I finally disconnected the correct fuel pressure sensor. With it disconnected as well as MAF sensor disconnected, I tried to start the car. It cranked but no start. While my scanner does read live data, I cannot find an RPM reading. If it matters, I do see the rpm needle move up a bit when cranking the engine. The pic is what I believe is the fuel sensor.
What are the three wire colors for the connector? With this sensor disconnected, did the previous pressure sensor fault code change?
If your scan tool could read live data, engine speed/rpm data would be found under DME module features.
Detection of rpm needle movement is good news. It means that the crankshaft position sensor likely survived the 7V surge on the DME 5V rail. The finding also suggests that the DME 5V rail is unlikely to be shorted to ground, which would lead to an inoperative crankshaft position sensor.
You scan tool is showing low battery voltage. It's important to maintain the battery at ~12.6V when trying to start the engine and when doing tests.
After the many start attempts, the engine may be flooded (cylinder walls and spark plugs coated in fuel). When you remove the oil dipstick, does it smell strongly of fuel?
Last edited by Maybe, maybe not; May 18, 2026 at 05:34 AM.
Maybe the battery is creating some of the issue. I purchased a battery check to see if the battery needs to be replaced. I will update once I get it. See pictures below. I will give each picture a description. Note, after disconnecting fuel rail sensor and MAF, I cranked the engine and no start.
Yellow, white and blue wires, hopefully the fuel rail sensor. After disconnecting fuel rail sensor and MAF, I ran the scanner and received these results. I cleared the codes and ran scanner again, and got these results. Same as above (results after clear). Cleared codes again and tried to start engine. No start and ran scanner. Received this code. Cleared codes and tried start. Crank but no start. Ran scanner and code popped up. Cleared codes again. Tried to start and crank only, no start. Ran scanner and these codes popped up. I was checking to find live RPM readings. This is the menu available for live data. This is the menu when I go into DME. I don’t see where I can find RPM readings.
Check for engine speed/rpm in Motor Operating Values.
The DME codes suggest that the DME is still healthy.
As you suspected, the two ABS-DSC codes, one IHKS code, and one CAS code are screaming "the battery is two weak!". You can't expect the engine to start without a strong battery.
When you have a strong battery in the car:
1) Keep the MAF sensor and Fuel Rail Pressure Sensor disconnected.
2) Leave a charger connected to the battery for the remaining steps.
3) Turn ignition on (engine off). Look at the battery voltage displayed on your scan tool. Do not proceed until the system voltage reads at least 12.5V+ stable.
4) Clear ALL fault codes from ALL control modules.
5) Read the DME codes before cranking. You want to see only the open-circuit/short-to-B+ codes for those two items, confirming the DME is happy
6) Perform the "Clear Flood Mode" procedure, which shuts off the fuel injectors, keeps the valves moving to pump out excess fuel vapor, and dries the spark plugs.
a. Sit in driver's seat and press the accelerator pedal 100% flat to the floor. Hold it there.
b. Push start button and let engine crank for 5 to 7 seconds with your foot still holding accelerator pedal 100% flat to the floor.
7) Attempt a normal start. Take your foot off the accelerator pedal. Press the brake, and try to start the car normally.
->Engine starts and idles: Let it idle briefly until stable and then shut off. Purchase and install new MAF and Fuel Rail Pressure sensors.
-> Cranks but no start: Immediately use scan tool to retrieve all fault codes, especially from the DME.
Last edited by Maybe, maybe not; May 22, 2026 at 06:22 AM.
Sorry it’s been some time. I was traveling for work, and didn’t get a chance to try your instructions above. Are you saying that I should replace the battery before attempting those steps? Or just charge it above 12.5V? I just want to confirm before attempting. Thanks.
Sorry it’s been some time. I was traveling for work, and didn’t get a chance to try your instructions above. Are you saying that I should replace the battery before attempting those steps? Or just charge it above 12.5V? I just want to confirm before attempting. Thanks.
If your battery struggles to hold 12.5V after charging it, then have a local auto parts store test the battery. Replace the battery, if necessary. If the battery is fine, connect a battery charger to it during any of your testing procedures to maintain the system at 12.5V.
