General Information On Checking/Correcting Headlamp Adjustment - AH82.10-P-1000-01A
Model all (4xWD, CAR, Light Transporter, Smart)
General
The documents on headlamp adjustment describe the left side of left-hand drive vehicles. Unless a different description is given, the procedure for the right side is the same as for the left side. On right-hand drive vehicles, the procedure must be performed mirror-inverted. On vehicles with level control and/or with dynamic xenon or LED headlamps, the engine must be running during the "Check/correct headlamp adjustment" procedure.
On vehicles with level control system or dynamic xenon or LED headlamps, adjustment of the headlamps by the Service department must be invoiced as an additional operation.
When checking the vehicle-specific headlamp adjustments the country-specific legislation and specifications from Daimler AG must be observed. The handling and application instructions for the device manufacturer for the country-specific approved headlamp aimers must be observed.
Otherwise it cannot be guaranteed that the headlamps concerned are correctly set, which can then jeopardize the road safety of the vehicle!
Identify chassis variants
Check if steel springs are installed at front and rear axle or using the data card.
Wheelbase-dependent level difference between front and rear axles
Effect of vehicle level on headlamp adjustment
Illustrated on model 166.0
Vehicle at headlamp adjustment station
Position vehicle towards headlamp adjuster (01)
Position vehicle with the driver-side front wheel (05) at the start of the approach line (06) and parallel to the approach line (06).
Drive vehicle on with the driver-side front wheel (05) exactly along the approach line (06).
The driver-side front wheel (05) must always run at the same distance to the approach line (06).
Only in this way, the geometric driveline axis of the vehicle will be aligned with the light box of the adjustment device (01) and correct headlamp check or headlamp adjustment is possible.
Due to the effects of different track widths at the front and rear 1
axles, mixed tires and/or drive line angle, the distance of the rear axle to the approach line (06) is ignored.
Test conditions
Before the headlamp adjustment is checked and corrected, the vehicle must be in a ready-to-drive condition.
Vehicle in ready-to-drive condition means:
Correct tire pressure, Correctly calibrated vehicle level incl. zero position adjustment, Steering is in straight-ahead position.
Additionally on vehicle without level control and headlamps without dynamic headlamp range control:
Vehicle unladen.
Checking and correction of the headlamp adjustment must be performed on a flat, horizontal surface.
Maximum permissible height difference of surface for: Vehicle: ±1 mm/m, Headlamp adjuster: ±0.5 mm/m, If the maximum permissible height difference of the surface is exceeded or the vehicle level is not correct, there will be a deviation (a) corresponding to the level difference (x) and wheelbase (y). In the example shown in the picture, a level difference of just 3 mm between the front and rear axle results in a deviation (a) which has an effect of approx. 0.1 % on the headlamp adjustment.
It is essential to fulfill the test conditions and follow the model-series specific instructions from the "Prepare vehicle for headlamp adjustment" documents!
Otherwise it cannot be guaranteed that the headlamps concerned are correctly set, which can then jeopardize the road safety of the vehicle!
Schematic diagram showing light-dark boundary
Light-dark boundary
The dark area (c) and the colored area (b) of the light-dark boundary of the low beams must be above the reference lines, as shown in the color display. Only the light area (a) of the light-dark boundary of the low beams must be below the reference line, as shown in the color display.
The exact shape of the light-dark boundary of the low beams depends on the model series and the headlamps and is shown in the corresponding "Check/set low beams" documents.
Otherwise it cannot be guaranteed that the headlamps concerned are correctly set, which can then jeopardize the road safety of the vehicle!
Illustration shows adhesive label for model 166 with halogen headlamps in ECE version
Headlamp version
For each specific model series, there is an ECE and SAE version for each headlamp variant (halogen, xenon or LED headlamps); different procedures for checking and correcting the headlamp adjustment are required for these different versions. The adhesive label (02) attached to the headlamp indicates whether the vehicle is equipped with ECE or SAE headlamps. Alternatively, it can be determined from the headlamp adjustment documents specific to the model series. In the example shown in the picture, the ECE version (03) is shown on the adhesive label (02).