P112f and p0171 codes

[XGoldenSpartanX]

2013 x1 35i N55 here, just got my valve cover, gasket, and crankcase hose replaced, and now getting a p112f, and p0171 codes. Any ideas what may have caused this? All BMW oem parts. Mechanic said he will look at it, but never had the issue before.

[bassrebel]

Originally Posted by XGoldenSpartanX

2013 x1 35i N55 here, just got my valve cover, gasket, and crankcase hose replaced, and now getting a p112f, and p0171 codes. Any ideas what may have caused this? All BMW oem parts. Mechanic said he will look at it, but never had the issue before.

Is your car acting any differently?

Did the tech clear the codes and they kept reappearing?

[XGoldenSpartanX]

Originally Posted by bassrebel

Is your car acting any differently?

Did the tech clear the codes and they kept reappearing?

No, it's not really acting any different, he cleared the codes, and they came back.

[NocheDeZippeh]

p112f: Manifold Absolute Pressure to Throttle Angle - Too High (Bank 1)

The fault is recognized when the relationship between the indicated intake manifold pressure and the mass airflow calculated based on throttle-valve angle is not correct.

Potential problem source(s):
-Measured value for intake manifold pressure (absolute) too high
- Check intake system and crankcase for leakage
- Check throttle valve (contamination, carbon deposits, icing)
- Check plug and wiring harness between intake- manifold pressure sensor and DME
- Vacuum leak within induction tract/crankcase
- Incorrect throttle-valve angle
- Pressure sensor defective
- Check plug, wiring harness at electric throttle- valve actuator
- Replace pressure sensor
- Replace throttle valve



p0171: Mixture adaptation, lower speed range: mixture at partial load too lean

The fault is recognized when the mixture is too lean and must be enriched by more than 25-30%, depending on load factor.

Potential problem source(s):
- Oxygen sensor before catalytic converter defective
- Mass-airflow sensor defective
- Defective injectors
- Intake-manifold pressure sensor defective
- Intake-air temperature sensor defective
- Camshaft position sensor defective
- Defect in high-pressure fuel system
- Defect in low-pressure fuel system
- Intake system leaking
- Oil cap not sealing
- Leak in exhaust system

- If additional faults related to the following components are present, process these first:
Pre-catalyst oxygen sensor, mass-airflow sensor, intake-manifold pressure sensor, intake- air temperature sensor, camshaft position sensor, high-pressure fuel system, low-pressure fuel system Check air-induction system for leaks (also checking the following components: Positive crankcase ventilation, oil cap, tank evaporative emissions system)


Sounds like it could be a leak in the new valve cover/gasket or crankcase hose?

[wheela]

Yeah, potentially a leak somewhere like NocheDeZippeh mentioned, or potentially the connection on the MAF sensor on the intake pipe between your air filter and turbo. I'd check that connection, maybe disconnect/reconnect it in case some crud got on the contacts and is throwing off the air flow reading.

Along the lines of leaks, it doesn't take much to throw things off at low load. I had high long term fuel trims (around 10%), and they came down to around 5% just by tightening the hose clamp on that intake pipe mentioned above. It already felt snug, but I guess it was still leaking in enough un-metered air to throw the fuel trim off around 5%.

[XGoldenSpartanX]

Just got it back, they found the valve cover they got was cracked, so they replaced it with another, and now they are getting the following codes:

2C57
28A0
3401

They smoked tested it, replaced a vacuum line, and nothing changed, no leaks anywhere else. They recommend taking it to a BMW dealership…. After I just spent $1100 with them…
Not happy.

[XGoldenSpartanX]

Fixed!!! Turned out the mechanic shop I took it too, didn't put the Valvetronic Actuator gasket back on. Causing a vacuum leak, and throwing all the codes. Thanks!

[wheela]

Glad you got it fixed! Thanks for reporting back what the problem was!

[Glene]

Originally Posted by XGoldenSpartanX

2013 x1 35i N55 here, just got my valve cover, gasket, and crankcase hose replaced, and now getting a p112f, and p0171 codes. Any ideas what may have caused this? All BMW oem parts. Mechanic said he will look at it, but never had the issue before.

I replaced the valve cover and the valvetronic seal, now I have the same two codes. Don't know where to start. Just hate BMW, so many issues.

[Gamb1t]

It's likely you or whoever did the job missed something if these codes never existed prior to the service work. Check and recheck everything.