'05 MCS 25k mi. First problem ever. Just went into "limp" mode as I was accelerating from an on-ramp. Searching past threads leads me to believe my problem/s may be MAP sensor/s and ByPass Valve. Although I see the BPV working at idle, it may not be fully closing or the spring may not be strong enough. Is this common to find that they throw these two codes together? Should I change out both the MAP and T-MAP sensors or just the MAP? Thinking of going w/the Detroit Tuned BPV since it's out of warranty and may as well get the added benefit of quicker response. NEthing else I should be investigating? Suggestions/help will be appreciated.

 

Have you checked the Crank pulley? If they start to seperate or come apart it can throw those codes also.

 

Interesting! Thanks for the tip. From the top, it looks o.k. but will jack up tomorrow and check it from underneath. It's a combination of harmonic balancer & crank pulley, right? am I looking for wobble/delamination, etc.?

 

Dodged that bullet! Just checked it this a.m. and found that I have the latest version CP (and my car is a 01/05 build date, too!). Even checked it with a strobe to see if it was wobbling. Thanks for the tip, tho. At least I know what isn't the problem. Going to get a new MAP sensor first, then if that doesn't solve it, on to a new BPV. Any other suggestions will be very much appreciated.

 

To check the MAP sensor connect an OBD scan tool and turn the key on but do not start the car. The tool should show a reading of 14.7lbf (101.325kPa) at sea level or sightly less at higher altitudes.

If the reading is way off remove the connector to the MAP and check for approximately 5VDC across two of the three wires with the key on.

If there is no 5VDC to be found you have a wiring problem and a new MAP will not resolve the situation.

The third wire is used to feedback a portion of the 5VDC to the ECU; how much is fed back depends on how much vacuum is in the manifold. The higher the vacuum the less voltage is fed back.

normally the operating range will be between 1 - 4.5VDC. Voltages outside of this range is reserved for diagnostics to detect an out of range situation.

Good luck and I hope this helps!

 

Frenchie, I don't have an OBD scan tool but did check the input voltage. 4.98v across red/white & brown/white wires. At least I know it's not a wiring problem. Question: If it is a bad MAP Sensor, would that throw both codes or are there two problems at the same time? Like throttle body or BPV? (laws of probability suggest not). Would my friendly ADVANCE AUTO store's OBD reader give the MAP Sensor info.?
Thanks for your help!

 

Just got back from ADVANCE AUTO. Reading of 99kPa/14.3lbft. @ approx. 800 ft. alt. which tells me that the MAP Sensor is o.k. Thanks for saving me that expense! W/o putting my foot into it, the car drives & idles fine right now and the CEL is off. Will run it thru a few more drive cycles b4 getting into the boost range. The only thing I could find and correct was a slight leak at my catch tank fitting. I would imagine that unmetered air would have the same effect as pulling the dipstick or removing the oil filler cap but can't imagine it throwing the codes P0107 & P1688. Am I wrong?

 

NE1 ever had one or both these codes thrown because of a slipping belt? I just checked mine and the hole wasn't showing on the tensioner tab, checked the belt and it was the stock CONTI 1388. Had a spare Goodyear 4060537 (6PK1365) and just installed it. With a 15% pulley, it was a tight fit but the hole is in view now. Obviously the orig. was tired after 25k mi. and probably 20 DE events. If this wasn't it, at least I've performed some good preventive maintenance.

 

Did that resolve the P1688 code?

 

Just had a look at my supercharger bypass valve while my engine was running in limp mode with a P1688 code displayed. Supercharger bypass valve is stuck halfway open or closed depending on your outlook.
Ordered a new one from Classic yesterday morning, this should put right it again. It looks to be a slam dunk fix to me. Hope this helps another DIY MINI nut.

 

The BPV should be open at idle, as there is no boost condition. If you're looking at it while the engine is idle, it's not a completely sealed environment, which means the valve may be behaving that way. When you accelerate hard, the valve shuts due to the difference in pressures. That's how you build boost. If the BPV were completely failed, you would get low or no boost. It should be completely shut when the engine is off.

The belt probably fixed his problem, although the 6PK1365 seems a bit short to me at 1365mm. That's the same as the Gates K060535. I currently have the JCW belt, which is 1374mm. That makes approximately one hole viewable on the tensioner shaft, or roughly 10mm. Stock belt length is 1388mm.

If memory serves, I thought one NAM post mentioned reseating the MAP sensor connectors. Try that as well.