Adaptation channels in TDI engines (Articles)

For VAG TDIs, various operating parameters can be modified through the "Adaptation" diagnostic function, provided a login with the code 12233 is performed (the idle speed can sometimes be adjusted even without a login).
Some MSG (V6?) systems use "26262" as the login.

Due to various inquiries in the forum, the function of the different customization options is explained here. A diagnostic tool like VCDS is necessary for the job.

The possible range of values for the adaptation inputs can vary from channel to channel and from motor to motor. Depending on the motor or software version, certain channels may also be locked.

To determine possible maximum and minimum values, you can provide very high or very low inputs. If the input exceeds the permissible range, the possible minimum or maximum value will be returned. Maximum displayed.

Experimenting with the adaptation channels without proper knowledge can cause motor malfunctions or damage!
Similar concerns apply to lotteries that involve any other (alleged) login codes: in such cases, there is a risk that... Software settings are being changed without knowing how to revert to the previous state!


Channel 1 modifies the pump characteristic curve, which is the relationship between injection quantity, RWG voltage, or delivery angle (in positive displacement pumps), and engine speed. The entire characteristic curve is shifted along the quantity axis.
Since this characteristic map is part of the closed-loop feedback system for air-fuel ratio control, a lower injection quantity is indicated for an increased air-fuel ratio at idle, and vice versa.

Translation assistance (thanks to Gremlin):
Activate as many consumers as possible (climate control, windshield heating, lights, etc.). Bring the engine speed up to approximately 2000 rpm using the accelerator pedal, and then maintain that accelerator pedal position without changing it.
Then, enter the new adaptation value. Based on the change in speed, the principle of operation becomes immediately clear.

The total play is only a few milligrams per actuation. Therefore, this approach is not suitable for significant tuning, but only for eliminating minor jolting issues (-> use smaller values) or bringing the rev-limiting speed within the desired range.

The effect can usually be read from the indicated idle speed.
In some engines (PD), based on previous experience, adapting channel 1 appears to have no effect at all.


Channel 2 modifies the idle speed.
The adaptation should be performed with the lowest possible engine load (i.e., with electrical consumers and air conditioning off) so that the idle speed control can reach the new value without fluctuating load conditions.


Channel 3 modifies the target air mass (important in EGR operation).
At idle and partial load, the amount of air drawn in without the EGR system is higher than the target air mass. The EGR valve is opened to the extent that the proportion of fresh air is replaced by exhaust gases above the target level.
If the setpoint is increased (resulting in the storage of higher values), the proportion of excess fresh air decreases, which in turn reduces the amount of exhaust gas being recirculated, and vice versa.
The effect can be read in field 2 (target value for LM) of form MWB 3.
Compensation for power loss due to insufficient mass airflow (MAF) sensor readings is not possible because the exhaust gas recirculation (EGR) system is closed at full load, and the fuel injection quantity is limited based on the actual MAF sensor reading (not the target value).


Channel 4 modifies the injection start map, which is the relationship between injection start, injection amount, and engine speed. The entire injection profile is shifted along the injection start axis.
The effect can be directly read from the MWB 4.
"Advancing the injection timing increases the peak pressures in the engine and can, for example..." ZKD (cylinder head gasket) failures are more likely, especially in conjunction with chip tuning!
In many digital cameras, channel 4 is locked and cannot be modified.


Channel 5 is changing the starting amount. In cases where startup problems seem unsolvable, increasing a certain value can sometimes provide a solution.

As a default value, it is usually set to 32768 or 128 (in older 8-bit message storage devices) across all channels.
When investigating mysterious errors, it can be helpful to first store these values.


Changing the preheating time:
Okay, I understand. Please provide the German text you want me to translate into English. I will only provide the translation.