P0171 Fuel Trim Lean - A4 Diagnosis

"This Audi has the following error code stored in the diagnostic memory: P0171 00 [237] - Fuel trim system (Bank 1) - System too lean. It appears approximately every two weeks."

I couldn't detect any leaks, and the lambda value remained constant even when spraying with a leak detection solution.

The oil drain plug can easily suck in oil; usually, they "pop" out when you unscrew them. Are there any known issues with the crankcase ventilation valve on this engine?

Address 01: Engine Control Module (------CDHB)
Label file: DRV\06H-907-115-CAB.clb
Part number SW: 8K1 907 115 D, Part number HW: 8K1 907 115.
Component: 1.8L R4/4V TF H07 0002
Revision: A5H07---
Encoding: 010C000C02070058
Operating number: WSC 99999 1023 2097151
ASAM Dataset: EV_ECM18TFS8K1907115D A01003
ROD: EV_ECM18TFS8K1907115D.rod
VCID: AF2E5551F6812F39C0-80FA

2 error codes found:
4629 - Main relay.
P068A 00 [096] - Opens too early.
Sporadic - unconfirmed - checked since last deletion.
2811 - Fuel metering system (Bank 1)
P0171 00 [237] - System too lean.
Warning light ON - confirmed - checked since last reset.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 2.
Mileage: 83,608 km
Date: 2017.06.22
Time: 09:01:42

Motor speed: 794.00 rpm.
Normalized load value: 22.4 %
Vehicle speed: 0 km/h
Coolant temperature: 67 °C
Intake air temperature: 32 °C.
Atmospheric pressure: 980 millibars.
Voltage at terminal 30: 13.970 V.
Lost learning counter via OBD: 40.

Readiness: 0000 0000

Hi,

How is the fuel pressure? Are the fuel filter and injectors clear and not clogged?

Best regards, Rainer.

I didn't check the fuel pressure, but I could have also checked it using VCDS.
The engine is running smoothly, without any issues.
Okay, so we're taking out the fuel injectors to inspect them?

I would first like to examine the additive and multiplicative learning rates of the Lambda regulation.
https://community.dieselschrauber.org/en/viewtopic.php?t=21836

Best regards, Rainer.

Evening.

"On the A4 8K, the crankcase ventilation valves often fail. If you're experiencing this issue, you might hear a hissing sound if you touch or manipulate the valve's "cover" while the engine is running."

Best regards,

dieselschrauber wrote:

I would first like to examine the additive and multiplicative learning rates of the Lambda regulation. I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL. Best regards, Rainer

I already looked for it yesterday, but I couldn't find a corresponding part number. Is it referred to by a different name for UDS control units?

The corresponding measurement labels vary depending on the control unit. Simply type "lambda," "fuel," or "mixture" into the advanced measurement blocks, and all entries containing that search string will be displayed.

Best regards, Rainer.

Yes, I tried, at least with Lambda, Ada, and Mul.

I will search for "gemisch" and "fuel" if I encounter him again.

"Color correction".

Best regards, Rainer.

It's normal for the oil filler cap to be slightly vacuum-sealed on 1.8L and 2.0L TFSI engines. However, if the crankcase ventilation (PCV) system is defective, the cap will be very difficult to remove.

Please provide assistance. DRV motor.

P087: Rail system pressure too low.
P0171: System too lean.
Speed: 1478 RPM.
Last 15.3%.
Speed: 54 km/h
Temp.: 96 degrees !!!!???
Temp.: 21 degrees (Normal??)
Pressure: 960 mbar.
Voltage: 14.224 V

[Translating...]

EOM

Again, what kind of engine?

Generally, a bit more text would be beneficial.

Benni wrote:

Again, what kind of engine? Generally, a bit more text would be beneficial.

PM for you.

Hi Sepp,

Please post the Autoscan. With the given information (which is far too little), you're just cluttering the thread. Who wants to read that? "PM?" You, if you're looking for help?

Best regards, Rainer.

Okay, here's the protocol.