Diag_VAG

в блоке ручника. датчиками через шину данных управляет ABS.
А что VAS в ведомом поиске неисправностей ничего не предлагает?
вот Росс предлагает:

Longitudinal Acceleration Sensor (G251)
Prerequisites:
System voltage at least 12.0 V.

[Select]
[03 - Brake Electronics]
[Measuring Blocks - 08]
Group 004
[Go!]
Check field 4, the value has to be between -1.5 and +1.5 m/s².
[Done, Go Back]
[Close Controller, Go Back - 06]

[53 - Parking Brake]
[Basic Settings - 04]
Group 020
[Go!]
Activate the Basic Setting.
[ON/OFF/Next]
The status of the Longitudinal Acceleration Sensor (G251) is now being displayed.
[Done, Go Back]
To make sure the basic setting was successful, check the sensor again.
[Close Controller, Go Back - 06]

[03 - Brake Electronics]
[Measuring Blocks - 08]
Group 004
[Go!]
Check field 4, the value has to be between -2.5 and +2.5 m/s².
[Done, Go Back]
[Close Controller, Go Back - 06]