[jayhawkc]

very long story real short. car ('08 335xi) goes into limp mode under acceleration with a cobb tune. Flashed it back to stock, same thing. The codes it was throwing were cylinder misfires. I replace the coils and plugs, still goes into limp mode, but this time throwing a P119A (TMAP on charge pipe). Start tearing into the engine, see the wiring for the MAP (on the manifold) has been chewed through by a rodent (never threw a P119B). Rewire the plug and harness, button up, still goes into limp mode but not throwing a P119A anymore, in fact not throwing any codes. Replace the charge pipe with a BMS charge pipe (stock diverter valves), still goes into limp mode. This time though it threw a P0442 (gas cap EVAP system). I can figure out how to fix that later, but my question is, is it possible that the car is going into engine malfunction mode because of that? It doesn't seem like a big enough issue for the computer to make it limp. I'm really at the end of my rope here.

Thanks!

[relative4]

Generic OBD2 codes are inadequate for this. Use a BMW-capable scanner.

[jayhawkc]

Originally Posted by relative4

Generic OBD2 codes are inadequate for this. Use a BMW-capable scanner.

any recommendations?

I've been reading a bit and I don't think it could be the HPFP. It starts on the first crank every single time. I'm going to clean the VANOS solenoids and try to fix the gas cap. Looks like I'll be getting a different scanner as well.

[e90yyc]

Car won’t go into limp mode from loose gas cap, no.

[gbalthrop]

Originally Posted by jayhawkc

...'08 335xi goes into limp mode under acceleration with a cobb tune...still goes into limp mode but not throwing a P119A anymore, in fact not throwing any codes. Replace the charge pipe with a BMS charge pipe (stock diverter valves), still goes into limp mode. This time though it threw a P0442 (gas cap EVAP system)...my question is, is it possible that the car is going into engine malfunction mode because of that?

Simple answer to simple question: NO! First of all, the engine is NOT running when the DMTL system operates (AFTER SHUTDOWN) to detect evaporative emission system leaks. There would be NO reason for that system to cause engine limp mode, as a fuel vapor leak into the atmosphere cannot harm the engine -- it is an environment issue related to evaporation of fuel and vapor entering atmosphere instead of being absorbed by the charcoal canister (and then purged to the intake when engine is running).

Here is the Definition of that Fault Code found in Bentley. BTW, it doesn't make any difference if you read a P0442 with a generic P-code reader, or "2A15" with INPA or ISTA, it's still a small leak detected in the Evaporative Emission System when tested AFTER engine shutdown:
P0442 | 2A15 | Evaporative Emission System Leak Detected (small leak)

If you don't like that definition, see BMW Fault Code Lookup where the result you get, when you enter EITHER P0442 OR 2A15:
N54 | P0442 | 2A15 | DME: Fuel tank ventilation system and purge air system, minor leak | MSD80 | Engine electronics

It IS always possible that you have a code saved in the DME that does NOT have a P-code equivalent. Water Pump Codes (2E81 - 2E85) are examples of that. However, less than a dozen DME BMW Fault codes listed in Bentley have NO P-code equivalent.

Are you SURE you don't have any Transmission, "4x4" (DXC), or DSC Warning light? There ARE certain faults that can save fault codes in those modules (OTHER than the DME) which can cause limp mode or power reduction.

If NO SES or other warning lights, and no code in DME other than P0442, time to get INPA Functional Jobs readout of any fault codes in ANY module (takes about 2 minutes), and then a more detailed connection to & testing of any Module which has fault codes, particularly DME, EGS, VGSG & DXC.

George

[jayhawkc]

Originally Posted by gbalthrop

Are you SURE you don't have any Transmission, "4x4" (DXC), or DSC Warning light? There ARE certain faults that can save fault codes in those modules (OTHER than the DME) which can cause limp mode or power reduction.

If NO SES or other warning lights, and no code in DME other than P0442, time to get INPA Functional Jobs readout of any fault codes in ANY module (takes about 2 minutes), and then a more detailed connection to & testing of any Module which has fault codes, particularly DME, EGS, VGSG & DXC.

George

Positive. It went into 4x4/DSC limp mode for about a minute after I disconnected the battery, but that was a while back and it hasn't done it since. I took it out today after replacing the charge pipe and everything was fine until I got hard on it, then instant limp mode. It threw the gas cap code as soon as I turned it on, that being consistent with your description of how that system works. At this point it's not throwing any codes that would cause limp mode. I guess my next step is to get this INPA thing and see if it tells me anything.

Is INPA a cable and a PC? I'm on a Mac, would it be easier for me to get that Schwaben reader or Carly for BMW? I guess I could dual boot this thing but I really don't want to install windows on it.

Thanks for your reply!