Performing static calibrations in-house and what you need to consider

July 29, 2021
Learn about equipment options and vehicle considerations you need to keep in mind when performing static calibrations in your shop.

If you’re delaying getting into servicing ADAS (advanced driver assist systems), don’t delay too long. Government safety agencies like the National Highway Traffic Safety Administration (NHTSA) and every vehicle manufacturer agree that ADAS saves lives and reduces collision damage. This means they’re here to stay and will continue to become more commonplace than ever in your bays. Many advanced (and profitable) repair shops are maneuvering their way through the complicated maze of ADAS sensor diagnostics and calibrations. But this will not be a simple or inexpensive endeavor. ADAS service joins a long list of other complicated technology challenges we’ve faced and conquered over the years in our wrenching careers. Today we’ll focus on the "human" side of ADAS – static calibrations.

Calibrating sensors – the “human” side of ADAS

If every ADAS-equipped vehicle could calibrate itself as well as it robotically performs its advanced driver-assist duties, those of us contemplating working on these vehicles could breathe a big sigh of relief. There is an overwhelming number of complicated calibration procedures and tools to juggle (Figures 1, 2). There are two main types of ADAS sensor calibration procedures:

  • Static — vehicle parked/system learning
  • Dynamic — vehicle driven/system learning

In most cases, both types of calibrations will require an enhanced OEM level aftermarket scan tool or true factory (dealer) scan tool. Some manufacturers require either static or dynamic calibrations, while others require both. Static calibrations (typically in your bay) require the most equipment, shop floor space, and time. If you are just beginning to do your research on what type and brand of static calibration equipment fits your needs (and budget) I must advise you of two big factors:

First, the equipment is costly. Whether you opt for a collection of pure OEM tools (as used by the dealers) or a choice from a growing list of aftermarket providers, plan on spending tens of thousands of dollars if you desire to calibrate multiple vehicle brands. But please keep in perspective that diagnosing pre-OBD vehicle drivability problems was best accomplished via a big box engine analyzer 35 years ago. The Sun machine my father purchased (and I used) in the 1980s cost more than $27,000. We made the ROI in a reasonable timeframe. With inflation factored in, that same investment would be around $87,000 today. That’s more than enough to handle your ADAS equipment needs with money to spare. Variations and choices are abundant in ADAS camera/radar static calibration equipment. The choices can be broken down into several categories and subcategories starting with OEM and aftermarket.

  • OEM/Dealer equipment — OEMs mostly use a geometry-based target placement process using common carpentry tools such as a plumb bob to find the exact center of the front (and back) of the vehicle (Figure 3). This allows a technician to locate and mark the vehicle’s geometric center.  Lines are then drawn on the shop floor (i.e., chalk lines/tape/markers) along with various angles to set the camera static calibration target(s) and radar sensor reflector (mounted on stands) at precise position/distances in relation to the vehicle (Figure 4). A factory scan tool is then connected to issue bi-directional requests to the ADAS sensor being calibrated. The scan tool tells it to lock on to that target to finish the static calibration process. Laser measurement instruments may be employed to speed up this time-consuming process.
  • Aftermarket – Stand-Alone target frame — An aluminum "frame" with arms to mount targets, lasers, and tape measures is set in place in front of the sensor being calibrated (Figure 5). As with OEM’s static calibration equipment, the position of the visual (camera) target(s) and/or reflector (radar) target must be precise. Wheel-mounted heads (with clamping brackets resembling chassis alignment heads) in conjunction with tape measures/lasers may speed up the process of finding the center of the vehicle. This is required to geometrically place the calibration targets in the precise location in front of the vehicle. This emulates the vehicle manufacturer's target placement position but can often take less time to accomplish compared to some OEM methods.  
  • Aftermarket – Target Frame with chassis alignment equipment integration — Because ADAS calibration procedures require the vehicle to be on a level surface, alignment racks (which must keep the vehicle perfectly level anyway) have recently become a handy piece of equipment to add ADAS calibration tools to. Several chassis alignment equipment companies are getting into the ADAS calibration tool market. Some aftermarket stand-alone ADAS calibration systems (i.e., Autel) can adjust the height of their target frame arms (and tool calibration software) to accommodate the raised height of the vehicle WHILE parked on an alignment rack.

The second consideration is weighing OEM vs. aftermarket ADAS calibrations. Some deem this a modern-day Hatfields vs. McCoys. While the OEM vs. aftermarket parts, info, and equipment debate is nothing new to our profession, ADAS has heated this feud. In the ADAS calibration debate, the “McCoys” cite the obvious; we’ve been using aftermarket tools to work on other safety systems for decades without the auto repair field turning into a disaster akin to the bankrupt asbestos industry. The OEM “Hatfields” cite multimillion-dollar lawsuits being filed (and won) by victims of accidents blamed on non-OEM service procedures. A Texas couple suffered severe injuries in 2013 after a near-fatal crash and resulting fire. Their attorney was able to put 75 percent of the blame on an OEM dealer’s collision center for using non-OEM body repair procedures on the vehicle before the couple purchased their used vehicle. The couple was unaware of the previous body damage when purchasing the vehicle from the dealer. On the previous collision repair, the OEM recommended the roof of the vehicle be welded in place. The insurance company paying for the prior owner's repair would only pay for the roof to be glued on, so that’s what the collision shop did. The result was the roof collapsing, which in turn caused other even more serious damage during the collision, resulting in a fire. The driver causing the head-on crash was only 25 percent to blame, according to the jury. Proof and blame don’t always align perfectly in the courtroom. 

Ready to give up on ADAS? Don’t!

If your business has a large volume of GM, Ford, and some FCA vehicles, complicated (and expensive) ADAS static calibration equipment is NOT required in many cases for the forward (windshield mounted) camera and long-range radar sensor (i.e., Adaptive Cruise Control) (Figures 6-9). Cameras in the outside rearview mirrors used for "around view" (a.k.a. surround view/bird's eye view) may still require camera targets (visual pattern target mats) positioned at specified distances from each side of the vehicle for static calibrations. Some Honda and Subaru models may also require both static (in the shop) and dynamic (on a road test) calibration procedures on their ADAS sensors. Toyotas are coming standard with ADAS systems these days and require static calibrations on their camera and radar sensors. Their factory calibration equipment is not overly expensive and any J2534 programmer will work well with a Toyota factory scan tool software (TechStream Lite) subscription. Further education and factory/dealer equipment on ADAS calibrations for GM, Ford, and Toyota aren't likely to bankrupt you as gradually get into the calibration field. 

Chassis alignment – cause or cure for ADAS calibrations?

Many OEMs advise performing an ADAS calibration if a chassis alignment changes the vehicle’s ride height. All OEMs (that I’m aware of) stipulate the thrust angle must be correct (no dog tracking) before performing an ADAS calibration (Figure 10). This makes total sense even if the steering wheel is not visibly off-center while driving straight. ADAS radar and camera sensor static calibrations rely on their targets being placed in exact positions relative to where the vehicle will be moving. Why go to the trouble of lining up the exact center of the front and rear of the vehicle in your ADAS calibration if that center line is NOT where the vehicle’s camera and radar sensors will be looking? On vehicles with negative thrust, the vehicles’ sensors will be looking toward the right instead of the vehicle your customer is following.

  1. The static calibration completes/passes on the scan tool, but the process was flawed.
  2. The OEM static calibration angle specifications state 2-3 degrees of sensor offset is acceptable, but the vehicle says “no” regarding the calibration process.  In other words, the actual calibration process displays “fail” on the scan tool.  If we had a preference between these two problems, most of us would rather fail a calibration that is more particular than the OEM numbers than have a calibration that says “successful” but is flawed.  

Is close good enough?

According to Dirk Fuchs, ADAS instructor for I-CAR, thrust lines that are off or ADAS sensor calibrations that are 1 degree off equate the potential for up to a 1.5-meter lateral miscalculation at 100 meters of distance between your customers’ vehicle and another vehicle. The result might be a false ADAS intervention (vehicle braking/stopping for no reason) or worse yet, an accident.

Vehicle ride height/sensor vertical accuracy

A favorite custom modification for many vehicle owners is changing the ride height of their vehicle with lift kits, lowering kits, custom wheels, and the like. This can make an ADAS sensor “look” at the pavement (instead of another vehicle) or “look” towards the sky. Potential missed hazards and false triggers can occur with vertical inaccuracies, too. Automakers are concerned enough about sensors having precise vertical calibration accuracy that many specify verifying the following before static calibrations:

  • Correct tire size and inflation
  • An empty trunk/cargo area
  • A full fuel tank

Wisdom from a mobile tech 

Shouldn’t ADAS Inaccuracies set DTCs? Sure – but shouldn’t other vehicle issues such as leaky EVAP systems and intermittent misfires? Sometimes you have false DTCs, sometimes you have real problems without DTCs. That’s just the nature of today’s awesome (but not perfect) automotive self-diagnostic technologies. To make that point, Mike Reynolds, owner of Mobile Automotive Service Solutions in Charleston, South Carolina, posted one of his case studies (complete with a video) on the Diagnostic Network. Mike was asked to look at a 2020 Honda Odyssey repaired by a collision shop after frontal damage. After leaving the collision shop, the customer noticed the Honda SUV’s adaptive cruise control did not function. Mike took the vehicle on a road test. After activating the ACC (Adaptive Cruise Control), the vehicle did not attempt the proper auto braking intervention while approaching another vehicle. A return to the collision shop for an inspection of the ACC radar sensor revealed a slightly bent mounting bracket missed during the collision repair. The radar sensor was essentially looking “over” the top of the vehicles it was following. The shop replaced the bracket, Mike performed the proper factory calibration of the sensor, and all ended well. 

Windshields tell a story

A close look at a windshield will tell a story. 

  • Quality glass/OEM windshield/clean? Obviously, a bug-covered windshield can cause camera issues, but so will poor quality glass as it distorts the camera’s view (Figure 11). Look at the logo on the windshield and do your research to determine if it’s what the vehicle needs. Glass quality and cleanliness issues may or may not set a DTC but can reduce the system's confidence/performance level (Figure 12).
  • Is there a disability mirror placard? While you’ll want to look for a disability license plate as well, disability placards commonly indicate the primary driver is older. Older drivers may need extra education and encouragement from the experts at their repair shop on how these systems operate. My in-laws are in their late 70s and purchased a used 2019 Chrysler Pacifica with all the ADAS features available this year. They regularly ask my wife or me to make sure their heated seats are off. They also try to remember to turn off the engine auto stop feature on each trip as well. My father-in-law worries the transmission is slipping due to a normal delay in engine restart/acceleration. Adaptive cruise control (ACC) and lane keep assist (LKA) are simply not good fits for them.
  • Is the lane camera overheating? This only sounds crazy but what happens when you put your phone on a windshield mount on a sunny day? It can overheat and shut down to prevent damage. The same is true for windshield mount ADAS cameras. Cameras and radars have heaters built into them. Those heaters can fail (like O2 sensor heaters burning out) and stay on. One GM PI (Prelim Info) bulletin states “cool the cabin down with the A/C to restore LKA and ACC functionality.” I understand the LKA part because it relies on a camera to “see” lane markings. But why would the grill-mounted ACC radar shut down from a windows-up/direct sunlight super-heated cabin condition? Because the two systems work together (sensor fusion) in several aspects of ADAS operation. Whenever circumstances merit calibrating one sensor, experienced techs recommend calibrating both the radar and camera sensor regardless of whether the OEM requires it. Using a more familiar analogy – what drivability tech checks fuel and ignores spark? 

Being certain – ADAS confidence

Confidence is not just a software level in an ADAS system. Confidence is another human side of the ADAS equation. Overall, ADAS features input far more positive variables into our customers’ safe driving experience than negatives ones. As repair techs, we mostly deal with broken vehicles and vehicle abuses. We rarely hear the positive side of vehicle safety systems – the injuries avoided and lives saved.  The worst thing the repair industry can do is to become a negative factor in the ADAS equation. Going forward, we must continue our education on the subject, carefully research (and purchase) quality calibration equipment, document every process involved and follow every instruction from the vehicle manufacturer whenever performing calibrations. Comedian Tracy Morgan asks in his latest Rocket Mortgage TV commercial, "Why be pretty sure when you can be certain?” When performing static calibrations, it makes sense to be certain at every step!         

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