Professional_Tool_And_Equipment_News_February_2020 - 52

minimal amount of fuel, tire size and
pressure, and other factors that might
affect the weight and balance of the
vehicle. Consult the latest vehicle service
information for requirements.

CASE STUDY

When working on a 2019 Nissan Altima,
the service information states that the
technician must always perform the
radar alignment adjustment after removing and installing or replacing the distance sensor for intelligent cruise control
(ICC). As mentioned earlier, these sensors are very sensitive and most include
a large warning label stating not to drop
the sensor, as shown in Fig. 1.
Most component manufacturers state
that if the unit is dropped, it should be
scrapped and replaced. It is important to
keep this in mind when performing such
services. For instance, a technician may
find themselves performing a radar calibration as a sublet for a body shop. They
should be asking themselves, "Why am
I calibrating this sensor?" If the reason
for calibration was due to a collision, the
technician may want to consider requesting a new sensor.
It is possible that a vehicle could have
been involved in a collision without
the sensor sustaining any visible damage. I have observed radar sensors that
appeared normal but presented difficulties or were impossible to calibrate,
ultimately requiring the sensor to be
replaced. I've also seen sensors opened
for inspection revealing internal damage.
Keep in mind that the service information may require that the vehicle
undergo a proper wheel alignment with
the thrust angle set to zero. When preparing for an alignment on a vehicle
with ADAS, the technician needs to
ensure that the vehicle is placed on a
level surface and meets all other vehicle
preconditioning states as outlined in the
service information.
Here are a few tips that may be useful
when tasked with ADAS calibration:
* Always perform a full vehicle scan
for diagnostic trouble codes (DTCs)
and make sure that all of the modules the vehicle is supposed to be

PTEN

FEBRUARY 2020

equipped with are reporting. Some
aftermarket scan tools may only
show modules currently present on
the bus system.
* Scan the system(s) and data parameters and record them. For forwardfacing radar, pull up the distance
and relative speed parameters and
place them in graphing mode.
Have an assistant ride along and
observe the data while following
other vehicles. If a very erratic signal is observed, this is indicative of
a damaged sensor. Fig. 2 illustrates
the performance of a damaged sensor. It is recommended that technicians scan several vehicles in order
to gain knowledge and awareness of
what's normal and what's not.
* When parking the vehicle in the
bay, have the scan tool connected with the steering wheel angle
data parameter displayed and set
the steering wheel to achieve a
0 degree reading.
* A battery maintainer is strongly
recommended to ensure the system
voltage stays in a safe range.
The radar alignment process involves
a reflector plate to be placed front, center,
and square to the center line of the vehicle. Additional special tools are required
in order to establish the center line of the

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Fig. 2 - Erratic relative speed and distance
from a defective radar sensor, outlined in red,
indicate sensor damage.

vehicle relative to the rear wheels (thrust
angle). You'll find that the setup process
is usually the biggest challenge. However,
after performing several calibrations,
technicians should find their efficiency
improving greatly.
There are several aftermarket tools,
such as the ones shown in Products to
Stock on page 53, which help streamline
the process.
With the vehicle on a level surface
and the alignment plate placed in its
exact position, a scan tool will be used
to request that the vehicle's onboard systems execute an alignment calibration
cycle. Once the request has been made,
the system will establish its offsets based
on the radar returns from the calibration plate. It is essential for technicians
to take the time to set up the calibration
tools properly. If everything is set up correctly and the onboard systems are in
good health, the scan tool should report
that the alignment is in progress followed
by an indication that the alignment has
been completed. Once complete, the
technician should observe the following
parameter identification data (PIDs) and
check them against reference values:
* Vertical angle - radar angle

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