I bought a 2009 fJCW, 68K on the clock. Car is clean AF. It has a 100 day warranty, and there was a small oil leak so I took it to a Euro indy shop that works BMW/MINI/RR. I literally took it there 4 hours after owning it. Oil leak fixed, but shop says firmware from Mini was June 08 (R056-08-06-510), and was updated to June 09 (R056-09-06-510) and that's where it sits. Suggests updating to March 17 build (R056-17-03-504). I paid for this as warranty company declined. So that's done. I pick up the car, no troubles. It sat 3 days, I get in and jump on freeway. Uphill onramp (I'm in AZ, uphill means wasn't flat, nothing special). Normal gear rowing, hit 65, shift into 6 and cruise. BAM. Yellow half-engine light. Loss of power, limping along. Feels like suddenly towing or e-brake is on. 20 seconds later, light goes out, power restored, no trouble the next 15 miles home.

I call the shop, says bring it in. Six codes pulled:Warranty approves MAF, valve cover, Vanos solenoid, knock sensor and after-cat O2 sensor. I paid for before-cat O2 sensor. Codes cleared, come get it I'm told. I leave the shop, jump on freeway, another "uphill" onramp, level off at 65, drop into 6th, BAM, yellow half-engine light again, limping. It heals in 20 seconds again. I call shop and they say bring it back. Only getting 2D50 and 2D9B codes now. They replace all 4 coils with Delphi's and Bosch plugs, send me on my way. I fill it with Chevron 91 and make it home ~20 miles away and park it. The next day I hot lap the free way onramps 11 times - all clear, heading home and while descending a long 65MPH transition ramp BAM yellow half-engine light, limping again. It heals again in 15 or 20 seconds. Over a minute since I'd "been on it"; just cruising along.

I find out a guy near me is a former MINI tech who suggests it may be carbon on intake valves. So I have the walnut blast done. Drive home goes well. Maybe it's healed? LOL. Negative ghost rider. This morning I jump on the freeway and same damn thing. As soon as I let off the throttle to cruise in 6th BAM yellow half-engine light. Again it clears. I pull codes, same two are back: 2D50 and 2D9B. So I bite the bullet and take it to the dealer. 45mile freeway drive no trouble. Tank is low so I put in 5 gallons, then as I'm cruising in 4th ~40 MPH BAM yellow half-engine light and limping. First time it's happened on surface streets. It clears again. Car sitting at MINI now.

So, new Vanos solenoid (Pierburg), new knock sensor, new valve cover (Febi), new MAF, new coils (Delphi), new plugs (Bosch), de-carboned intake valves. No other codes appear. I just don't get it. Verified new valve cover is holding vacuum around 38-40. I suggested to the SA @MINI that I was concerned about the firmware update playing a role in this. Unfortunately, I didn't have the car long enough on the '09 firmware to see if this would have happened since it literally went straight to the shop.So may questions. I appreciate any feedback! Also, does this **** show mean I've paid my entry dues into club MINI? Sure feels like I've been jumped in...

 

My gut says high pressure fuel pump, or crappy gas. When I lived in Connecticut , my car would “super knock” unless I filled up with gas from Sunoco. It didn’t like gas from any other station. In New York, couldn’t car less where I fill up from, it runs better from certain brands. Even still, it would give half engine light / half power for any of those events… I know a failing fuel pump can cause misfires and knocking, and will throw a half power engine light. Hopefully the dealer can find it.

 

Found this (link below). Hope it proves helpful.

https://static.nhtsa.gov/odi/tsbs/20...49464-9999.pdf

 

It’s a long weekend so not expecting to hear back for a few days. HPFP would be great - let’s get it done under warranty. Does a HPFP throw pressure codes? I get none. It’s sure a tough one. I kind of think wiring but I have no lift and metering the circuit is not possible.

thanks for the TSB. Not sure if N16 will spill over to my N14, and yesterday was about 100F when I was on the road but it does seem inline with my thinking about the flash. We shall see…..

 

I had a '09 Just with the same knock sensor code P0328 (HEX 2D9B). 2D9B is a Knock sensor "High" code. Simply throwing a knock sensor at the car is not trouble shooting.

The "High" code means the DME is not seeing a voltage drop across the sensor. What would cause this?

1. The connector is disconnected from the sensor.
2. Yellow wire from the DME is cut.
3. Black signal return wire to the DME is cut.
4. Faulty DME.
5. Faulty knock sensor

In my case it was the DME (no 5 volt reference signal); I had to change my engine computer.

The problem with troubleshooting is where this knock sensor lives. If you have a multi-meter, disconnect the connector from the knock sensor. Then backprobe the yellow wire and turn on the ignition; you should have 5vDC. No voltage means you have a bad wire or no 5V signal coming out of the DME. If you have voltage on the yellow wire; reconnect the connector and backprobe the black wire; you should see about 2.5vDC (voltage drop through the sensor). Further testing requires a lab scope.

 

@mkov608 best info I’ve seen on this, and I feel like I’ve been reading for solutions for weeks now. Thanks for the info!

I have not seen where the code means an open circuit so maybe it’ll be an easy issue for the tech. Fingers crossed!

 

I got the info from Mitchell1 (Snap On).

Most cars are using 5 volt reference circuits for things like camshaft sensors, camshaft sensors, vehicle speed sensors etc. Some vehicles (older Chrysler products) used a 9 volt reverence circuit, and some use a 12 volt reference circuit. In these circuits, (like a 3 wire hall-effect camshaft sensor) you have a + 5 volt signal coming in, a ground, and a signal wire going back to the engine computer. The signal wire provides a 5 volt square wave signal that is used by the computer. As with any electrical circuit (conventional theory) the voltage drops to zero on the ground side of the circuit, but if there is no current flow (open circuit) there is no voltage drop, and you will see a "sensor high" fault. Conversely, if there is a short and all the power is dumping to ground, you will get a "sensor low" fault.

PM me your email address and I'll send you the fault details.

 

You might find this interesting.

https://www.pelicanparts.com/techart...eplacement.htm

 

@njaremka wins… crappy gas apparently. MINI tech pulled the fuel line, collected some in a cup, said it smelled like varnish. I had put 3/4 tank on first fill up and added a few gallons before taking it in, and even after that dilution apparently it was **** still. Drained all gas, replaced LP line to HPFP (broken release clips), cleaned injectors and filled it up with new gas. I’ve put ~120 miles on it and so far, so good.

Here’s the crazy part. According to Carfax, orig owner sold it 11/18/2022 @68,381mi. I bought it 7/25/2023 @68,425. It was down one candy corn or two when I got it. It would seem very likely the tank I received was ~8 months old. Can’t believe I didn’t catch this with all the effort put into this.

Fingers crossed for sure.