VOLKSWAGEN PASSAT CAMERA CALIBRATION
◀ The VCA is inserted into the EOBD socket. This professional tool works wirelessly, via Bluetooth, where information is passed to and from the diagnostic hardware.
▶ Battery voltage must not be allowed to drop below a certain level, which varies between different car models. An extra power supply must be provided to avoid the risk of corrupting the ECUS.
Handheld tools with integral screens are popular for both professionals and Diyers but, for greater clarity, we have used the larger touchscreen from Hella Gutmann Solutions’ mega macs 77 model.
While you can enter the vehicle’s ID by make and model, a far more accurate method is to have the diagnostic tool recognise the car by its VIN number. For this, the ignition must be switched on.
In this case, the registration number and mileage are entered. This is so the calibration results are shown on a printout – ask a garage to provide this information post-calibration.
◀ A full global scan will reveal which ECUS are present on the vehicle, by interrogating them for any errors – this may be the first time you discover its full specification.
▶ This readout shows ‘(!)’ for ECUS possessing a fault code, ‘0’ if an ECU is recognised but there are no faults, and ‘---’ if an ECU is not present. This car, therefore, is not fitted with a rear camera, or main beam assist.
◀ Any errors within an ECU are logged as fault codes. At this stage, the diagnostic tool interrogates each ECU in more detail and lists how many fault codes have been recorded.
◥ If you are working on someone else’s car, let them know if other fault codes are found, so you are not blamed for causing them. Here, we are interested in the ADAS distance control fault.
◀ This professional machine shows not only the fault code but also gives an explanation. Basically, this is a Canbus error, which may be caused by a calibration conflict.
▴ The fault code is deleted. As it clears and does not come back, it seems as though this is a temporary fault, but a calibration should still be carried out to eliminate alignment as a factor.
▴ On this diagnostic machine, front camera calibration is accessed via a basic settings menu, then a camera calibration menu. Three different camera options can be selected for this Volkswagen.
◀ About 99% of the time taken to conduct a static camera calibration is involved with set-up. As this list is fairly elementary, we will focus on the last five items that involve the camera and sensor calibration (CSC) tool.
▴ The front camera is located behind the windscreen on this car (arrowed), but it can carry out more than one function depending not only on make and model, but also individual car specification.
▴ The front camera is calibrated using a CSC tool to which is fitted a non-reflective calibration board containing markings bespoke to each make/model, which must be positioned accurately (see Step 17).
▴ While it is not being calibrated here, radar sensors that control functions such as auto-brake and distance cruise control need calibrating separately with a different metal reflective plate.
◀ Things get more complicated on newer cars with side-mounted cameras for all-roundvision. Older cars with front cameras and radar systems have different calibration boards that are numbered.
▶ The distance between the centre of both front wheel hubs and the CSC tool is measured using a wheel mount (which is fitted and levelled) and a laser measuring device mounted to the CSC tool (see inset pic).
◀ Wheel mounts are removed from the fronts and fitted to both rear wheels. They must also be levelled. This exercise is to check that the rear axle and the CSC tool are parallel.
▶ Each mount’s laser beam (which travels in a straight line) is activated. The light is reflected into the CSC mirror and back onto the graduated scale. However…
◀ …while the readings themselves are of no relevance, the offside and nearside readings must be the same or within one digit of tolerance.
▶ If the readings are not the same, the operator must move the CSC tool carefully, until they match.
◀Finally, the board is levelled and its height must be set to the car-maker’s specification, mentioned on the diagnostic tool (see Step 13). The CSC tool has a graduated scale for this.
▶ Finally, the car’s ride height is verified again using a laser measuring tool that takes a figure from the centre of the wheelarch to the floor – this accounts for sagging suspension springs.
◀As the ride height is so important (note that some cars require a full tank of fuel), the figures are entered into the diagnostic equipment, which influences the calibration.
▶ Once selected, the calibration takes place within seconds. Here, the camera specifications are provided with the confirmation that the exercise has been completed successfully.
◀When prompted, the ignition must be switched off and on again. It is wise to open a window and reach through rather than to open the door, which can move the car and affect certain ECUS.
▶ A full global scan is performed again to check that the work has not affected any other ECUS. Here, it is noted that the radar distance control sensor has recorded a new fault code.
▴ Closer interrogation shows that the radar sensor lost communication with the camera as it was being calibrated. This is normal, because the camera goes offline during the procedure.
◀ As the fault code was cleared successfully and did not return, the ignition system was switched off and the VCI disconnected from the EOBD port.