Are you radar ready?

July 1, 2019
Take a look at these practical tips for Automated Driver-Assistance Systems.

Are you “radar ready?” Don’t want to mess with the new complicated radars and smart cameras on today’s cars and trucks? If you answered “no” to either question, are you planning on doing any 4-wheel alignments on newer vehicles? How about radiator replacements? You might want to check for the presence of an ADAS (Advanced Driver Assistance System) system prior to your next repair procedure. Both scenarios have the potential to create the need for an ADAS calibration. A long-range radar sensor offset of just 0.040” (visualize a spark plug gap) can make a difference of 40 feet (left or right) down the road for your customer’s adaptive cruise control. For the sake of argument let’s say you do get a radar sensor off calibration enough to adversely affect the system. This scenario could leave the potential for 3 different outcomes:

  1. PREFERRED OUTCOME — The onboard diagnostics within the adaptive cruise control sees the radar targeting information as erroneous, sets a descriptive DTC and promptly disables the system until repaired/calibrated.     
  1. UNDESIRABLE OUTCOME — By itself, the vehicle slams on its brakes to avoid a perceived head on collision when the inaccurately calibrated radar sensor for the adaptive cruise control misinterprets an oncoming vehicle safely in its own lane as a vehicle directly in front it.
     
  2. TRAGIC OUTCOME — Your customer’s vehicle plows into the car in front of it while your customer is not paying attention or placing too much trust in his/her radar cruise as the inaccurately calibrated radar sensor “stares” off into an open field instead of at the vehicle directly in front of it.

Outcome No. 1 will take some education and equipment to correct but sounds pretty good compared to Nos. 2 and 3 where property damage, injuries or even deaths may result.

Your customer’s vehicle may say “Radar Ready” but are you Radar Ready? Today’s ADAS (Advanced Driver-Assistance Systems) equipped vehicles have tons of new technology for techs to learn to diagnose, repair and educate customers on!

The business side of ADAS

If you think you’ll dodge the bullet on this new technology (i.e. your shop doesn’t do hybrids, diesels, etc.) you might want to rethink that. As we move at lightening speeds to integrate this technology into the average car or truck (ADAS is not just for luxury cars anymore) it is likely to become the next airbag or ABS system – meaning most every vehicle will have it. The popular prediction from tech-savvy industry leaders is that privately-owned vehicles will be replaced by completely autonomous ride share vehicles that pick you up and take you where you want to go. In some vehicular congested urban locales this seems practical at lower speeds in controlled environments if infrastructure is improved.

Need a new RADAR? Purchase a tail light assembly and Ford includes one for free!  This F-150 houses the rear RADAR sensors for BLIS (Blindspot Information System) and Cross Traffic Alert in the tail light assembly. The front sensors are behind the front bumper facia This Toyota’s radar used for adaptive cruise is mounted directly behind the Toyota logo in the center of the grill.

The full autonomous ride share approach to transportation will also be a huge help to those who aren’t close to mass transit and are unable to drive a vehicle on their own for a variety of reasons including cost, health, age and disabilities. However, in rural areas with higher speeds, careless drivers (just do a Google search on “ADAS Abuses” to see what I mean) where many conventional freedom loving Americans live, the autonomous ride share micro buggy seems quite a way off in my opinion. Regardless of the timing and details of ADAS evolution, there are plenty of ADAS-equipped vehicles roaming the roads right now in need of service. In order to gain a level of understanding enough to diagnose and repair ADAS let’s peel back two of the layers of technologies (Radar and Camera) that go into these complicated vehicles. A third technology layer (LiDAR) which constantly scans with lasers (at a frequency not visible to the human eye) instead of a camera in order to view the vehicle’s surroundings. LiDAR is relatively new to ADAS so it’s unlikely you’ll encounter LiDAR equipped models in your service bay anytime soon.

(Image courtesy of Mitchell 1) Do you have to calibrate with targets or a scan tool? Both or neither? Mitchell 1 has added a brand new quick link choice once you select a new vehicle to research. Simply click “ADAS” from the main menu to get the screen shown above for this 2017 Cadillac CT6.

Technology layer 1 – Radar

The days of radar being expensive, heavy and noisy (from internal moving parts) are long gone. Today’s radar sensors are solid state with no moving parts, are the size your hand, weigh just a few ounces and can cost less than $100 to manufacture. Some of today’s vehicles may have several radar sensors mounted all around them forming a “360 field of view” creating a ‘cocoon’ of awareness and safety around them. Radar sensors now scan electronically using multiple beams to send a radio signal at a reflective object in order to get the same signal bounced back. The delay in time it takes to get the signal bounced back equates to a distance. The rest is a lot of complex trigonometry embedded in advanced software. Radar sensors operate at extremely high frequency which gives them the name “millimeter radar.” The higher the frequency, the shorter the wave length.

  • 25 GHz Ultra-Wide Band Radars
  • 24 GHz Narrow Band Radars
  • 76-81 GHz Multi Mode Radars
Multiple ADAS systems means multiple radar beams scanning for targets ranging from a child on a tricycle when you’re backing up to a motorcycle in your blind spot when you change lanes.

Technology layer 2 – Smart Cameras

Cameras have been used for BUA (Back Up Aid) for many years prior to ADAS. BUA cameras are divided between the more conventional BUA cameras that use composite video signals operating like an analog audio signal and the newer digital variety that transmit video signals via a CAN bus message. All the ADAS forward facing cameras I’ve encountered are of the digital CAN bus variety. These “smart” cameras send CAN bus signals with message packets representing video images. The digitized images are then analyzed by a video processor module in order to determine exactly what to do with the information.  That information is used in systems such as lane departure warning, lane keep assist, lane centering/autonomous steering, pedestrian detection, and forward collision alert/avoidance.

Radar and Camera service concerns & calibrations

Both radar and smart cameras (in most cases) require some sort of initialization when installed as most modules do these days. This presents a challenge for some aftermarket scan tools trying to do all things for all vehicles. Radars and cameras also may need set up via a static calibration. Typically, cameras will require a certain target board with a specific size and pattern on it. Radars typically use a metal triangular shaped metal dish to bounce their signals off while calibrating. Both camera and radar calibrating targets require EXACT placement for accurate sensor static calibration. The position, distance and height of the target cannot be off even a little. This requires a lot of space in the shop, attention to detail and patience. After the static aiming / calibration there is usually a follow up required with a dynamic calibration, which also requires the right scan tool to initiate the procedure. Dynamic calibrations set into motion by the scan tool require driving on a “target rich” road. Target rich means the sensors see lots of things for the learning/calibrating process. Fence posts, road signs, guard rails, etc. all speed up the process of dynamic calibrations.

Beyond DTCs: Quick Functional Test 1 – Heat Signature

Every radar sensor I’ve encountered produced a heat signature.  Some brands run hotter than others. The sensors on this Chevy located behind the rear bumper cover were running about 5 degrees F. warmer than the surrounding areas of the bumper. While this doesn’t tell you how well the sensor is working, it will certainly pinpoint a sensor that is dead from a lack of power, ground or completely inoperative. 

Health / Safety Note: if the radar is warm – it’s emitting radar signals. I’m not aware of any official studies on health issues for techs leaning up against a bumper or grill for prolonged periods. However, there have been reports of male infertility issues that were blamed on radar sensors. Pulling the fuse for the ADAS systems prior to long periods of fender side leaning (with the ignition on) might be something you would consider doing just to be on the safe side if you’re planning a family
  • Radars do NOT like certain aftermarket grills, certain bumper stickers, bumper covers/bras and in some cases certain types of custom paint that may obstruct the ability of the radar signal to be received once it bounces back after hitting the target.
  • On some vehicles the bracket for the long-range radar can become easily bent which can drastically throw off the radar’s calibration.
  • Front camera may also need a static calibration if its aim becomes offset after collision / body

Beyond DTCs: Quick Functional Test 2 – Radar Detector

On many of the side (medium and near range) radars using the lower frequencies (24 & 25 GHz) a radar detector can be used to see if the sensor is at least  functional.

Repairs or other repair procedures:

  1. Service procedure in proximity of the camera (rear view mirror replacement)
  2. Vehicle center angle or trim height changes after a wheel alignment, suspension modification, or alternate size tire & wheel installation.
  • Smart cameras need a clean windshield free of excessive dirt, bugs, snow, and ice.  Excessive amounts of blockages may result in symptoms ranging from subtle reduced performance to a DTC with DIC messages alerting the driver that the system is currently unavailable.
  • Smart cameras also need a distortion free windshield.  Some aftermarket replacement glass can be problematic. 
  • Smart cameras typically have a 12-volt electric heater element in them to keep the portion of the windshield directly in front of them free of ice, snow or fog.
  • Smart cameras can overheat from too much sun load or a malfunctioning internal heater element.  Some cameras even contain fans in them to prevent overheating.  One Cadillac dealer tech told me he had to put a heavy glove on to handle the camera when removing it from its mount after its been on even for just a few minutes.

Beyond DTCs: Quick Functional Test 3 – Factory Scan Tool PIDs

The scan tool PIDs available on the Toyota factory Techstream for this 2018 Camry’s front recognition camera make it clear that heat is a big factor for these windshield mounted cameras. Excessive heat can cause a system inhibit followed by a recorded history event to tip you off in your diagnostics.

Beyond DTCs: Quick Functional Test 4 – Aftermarket Scan Tool PIDs

Most scan tool PIDs simply give the power feed status, DTCs status, disable history and maybe the software calibration p/n. This late model Ford’s BLIS (Blind Spot) Left Rear short range radar sensor’s multiple beams came up as data PID choices on author’s Auto Enginuity scan tool.  The PIDs were being graphed while on a road test. The same PIDs are NOT available on Ford’s factory IDS tool.  While knowing the distances each beam is targeting an object won’t likely be a diagnostic question in a factory trouble tree, the fact that they are changing as you drive past objects at least gives a very quick indication that the sensor is indeed powered and functioning.

EXCERPT FROM BMW SERVICE INFORMATION TSB SI B66 21 16
Applicable to 2015 BMW 228i Convertible (F23) L4-2.0L Turbo (N20);

There are two categories of system limitations – those that can be eliminated and those that are beyond control. The following table details possible limitations and what, if anything, can be done to eliminate or explain them.

Limitation Recommendation Notes
Obstructed camera view Remove obstruction Clean windshield
Replace wipers
Calibration incomplete Complete calibration Calibration is a lengthy process. Some features may not be functional during calibration. No faults stored during calibration period. Calbiration needed after windshield replacement.
Calibration failed Diagnose with ISTA Fault code 0x800AC4 - Camera calibration unsuccessful stored in KAFAS memory >3 times
Weather conditions Inform customer Possible situations: heavy rain, snowfall, ice, fog, blinding sun (strong back light), tunnel entries/exits (transitions into light/dark)
Non-typical surrounding vehicle Inform customer Possible situations: Rear of vehicle poorly illuminated, extinguishing taillights, custom rear body shape, carried load (log truck), open trailers, open tailgates
Surrounding vehicle/pedestrian Inform customer Possible situations: Sudden movement in traffic, too close to/on highway
The greatest challenge by far with ADAS is the need for dynamic calibrations on both radar sensors and cameras in the shop. The proper scan tool is not the only tool you’ll need. For the initial static calibration, you’ll need the proper kit consisting of pipes, brackets, squares, plumb bobs, levels / lasers, a tape measure and string. If that wasn’t enough, you’ll also need a flat and level shop floor with well over 21 feet in front of the vehicle of unobstructed space to set the various targets.  Triangular shaped metal dishes are used for reflecting radar and printed patterns are used for aiming the vehicle’s camera. Shop is small so just do static calibrations outside? Most of OEMs direct you to use tape or markings on the shop floor as you basically perform a large scale geometry equation to find the exact center of the vehicle at an exact distance from it.

Customer education

In the above chart from the BMW TSB the phrase “Inform customer” was repeated. If you read the entire TSB there are numerous photos and tips to pass along to customers. One important point to remember when interviewing customers with complaints for anything steering related is to find out if the vehicle has an ADAS system that involves lane departure warning, lane keep assist or semi-autonomous steering (at any level). Is your customer complaining about a phantom vibration? Lane departure warning may warn the driver they are not holding their lane (the smart camera determines this) with an audible sound and/or vibration in the seat or steering wheel. Lane keep assist will integrate with the electric power steering in the attempt to maintain the lane. Failure to use directional signals has resulted in more than a few customer complaints of steering symptoms. “I think I’ve got a worn-out tie rod” or “it feels like a tire pulling” may be what the customer suggests but if the vehicle has LKA we need to diplomatically ask “do you occasionally change lanes w/o using your turn signal?”  As with any new technology, sometimes the only thing that needs fixed is the customer’s knowledge level. Hopefully we’ve increased your ADAS knowledge level and you’re on your way to being radar ready!

About the Author

Dave Hobbs

Dave Hobbs is a senior technical trainer and curriculum developer for Delphi Technologies Aftermarket at BorgWarner Inc. He's Master ASE-certified with L1 (advanced engine performance) & L3 (hybrid) specialist certifications.

He has extensive OEM service and field engineering expertise, with more than 30 years of experience in troubleshooting vehicle systems electronics, with 15 of those years in the independent aftermarket repair business.  He has 20 years of experience in training engineers (worldwide) and service technicians in both the OEM and aftermarket arenas, as well as experience in working with postsecondary vocational / community college students as an adjunct instructor.

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