Headlamp Alignment Sensor: Adjustments
Left Front Level Control System Sensor -G78-, adjusting
Special tool, testers, and auxiliary items needed
- VAG 1551/1552 Scan Tool (ST) or VAS 5051 Vehicle Diagnostic Testing and Information System tester.
- VAG 1551/3B Adapter Cable
Prerequisites
- Vehicle must be standing on all four wheels on a flat level surface.
- Handbrake lever must be in off position and a drive gear must not be selected.
- Steering must be in straight-ahead position.
- Vehicle must be unoccupied and not loaded.
- Vehicle must not be moved during basic settings process (i.e.: opening and closing of doors, people leaning on vehicle, people entering vehicle is not permitted).
- If vehicle was raised using a lifting platform/hoist or a vehicle/workshop jack, then it must be rolled back and forth several times so that the springs etc. settle, before starting adjustments.
VAS 5051 Vehicle Diagnostic Testing and Information System or VAS 5052 Vehicle Diagnostic and Service System, selecting functions:
Testing and Inspection
VAG 1551/1552 Scan Tool (ST), connecting and selecting functions (function 01)
Prerequisites:
- All fuses OK., according to wiring diagram
- Voltage supply OK. (minimum 9.0 V).
- Connect Scan Tool (ST) using cable VAG 1551/3B.
Indicated on display:
VAG - SELF-DIAGNOSIS HELP
1 - Rapid data transfer*
2 - Flash code output*
* Appears alternately
NOTE:
- If display remains blank, check VAG 1551 voltage supply according to wiring diagram.
- Additional operating instructions can be called up with the scan tool HELP key.
- The key advances the program sequence.
- In operating mode 1 "Rapid data transfer" function 00 "Automatic test sequence" can be carried out The DTC memory of all vehicle control units is checked automatically with function 00.
- Switch ignition on.
- Switch printer on with the Print key (warning lamp in the key will light up).
- Press key 1 for "Rapid data transfer" operating mode.
Indicated on display:
Rapid data transfer HELP
Enter address word XX
- Press keys -2- and -9- to select 1 "Light control, left" address word "29".
Indicated on display:
Rapid data transfer Q
29 Light control, left
- Press -Q- button to confirm input.
Indicated on display:
Rapid data transfer Q
Tester sends address word 29
Control module version, checking
Indicated on display
7M3907391 EVG GDL + Auto HRC 0001 ->
Coding 00006 WSC 00000
Upper line:
- Part No. of control module 1)
- System designation (headlight range control)
- Version number 1)
Bottom line:
- Coding number 2)
- Dealership number
1) - Part and version numbers illustrated here are examples only
2) - Dependent on type of drive
- Press -> key.
Indicated on display:
Rapid data transfer HELP
Select function XX
- Press keys -0- and -8- to select "Read measuring value block" address word 08.
Indicated on display:
Rapid data transfer Q
08 - Read measuring value block
- Press -Q- button to confirm input.
Indicated on display:
Read measured value block
Enter display group number XXX
- Press key 0 twice and press key 2 once to select display group number 002.
- Press -Q- button to confirm input.
Indicated on display e.g.:
Read measuring value block 2
2.1 2.4 ADP. O.K.
- Loosen lower securing bolt -arrow- on coupling rod of front axle.
- Move coupling rod within elongated hole until specification of 1.0 to 2.0 Volt is displayed in display zone 1 of the Read measuring value block. Optimum specification = 1.0 Volt (if possible).
- Tighten securing bolt. When doing this ensure voltage remains as close to optimum tolerance of 1.0 Volt as possible.
Indicated on display after completion of adjustments e.g.:
Read measured value block 2 ->
1.0 2.2 ADP. O.K.
- Press -> key.
Indicated on display:
Rapid data transfer HELP
Select function XX
- Press keys 0 and 6 to select "End output" function 06.
Indicated on display:
Rapid data transfer Q
06 End output
- Press -Q- button to confirm input.
Indicated on display:
Rapid data transfer HELP
Enter address word XX
After completing the mechanical adjustment of coupling rod, the related electrical components must adjusted to the revised settings. Perform basic settings of the automatic headlight range control to adjust to the revised settings