Road Testing Vehicles After Repairs Today Not Like It Used to Be
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Road Testing Vehicles Not Like It Used to Be

Some vehicles today may require a dynamic road test after a post-repair scan to calibrate cameras and sensors, which is a far cry from the road tests of old.


Mitch Becker has been a collision industry trainer for 30 years and an I-CAR instructor for more than 25 years. Contact him at (763) 585-6411 or [email protected]

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When I visit shops to do training or help answer questions, I like to ask how they’re doing certain procedures. The reason I do this is so I can learn about any new ideas or solutions to ever-changing procedures in our industry. The surprising fact is how many shops don’t know what procedures I’m talking about. This really resonates with me as a trainer. I strongly desire for every person to know everything needed to be done for every procedure, but the problem is there is so much to know. I can tell collision repairers to look up procedures on websites or use I-CAR or ALLDATA, but there are so many changes to keep up with.


That is the reality we’re all facing. Technology is taking us all in directions we never dreamed of, much less prepared for. The technology improvements in computers and sensors have brought us to a major crossroads as an industry. Scan tools and recalibration tools are a major change to all of us. I know we’ve had scan tools for years, but now the depth to which we need to access the vehicle’s electronics is unprecedented for the collision industry. The mechanical repair side of the industry has much more experience with this kind of repair. The issue is that the requirements for electronics today go much further than many of us are accustomed to or comfortable with.



We’ve all been talking about pre-repair scans and post-repair scans on today’s vehicles. With advanced electronics, these scans become necessary procedures to evaluate what is damaged or has set diagnostic trouble codes (DTCs), commonly called codes or faults. These DTCs can be set at any time in a vehicle’s life and are the result of hiccups in the operation of either computers or their connections or even the computer codes originally used from the factory. Many of these codes may be set as the result of anything from minor communication glitches to a failure of a component. Unless the fault or code involves a major failure of critical components, the dashlight will not activate. This leads to the statement, “Just because there is no light does not mean it’s right.” These codes may just sit in the computer’s memory waiting for someone to notice them. When these codes are created is a critical factor to consider when repairing a vehicle. Codes not crash-related need to be singled out. Those that are crash-related need to be repaired correctly. So many systems are tied together and may share components, so if one component is damaged, multiple systems may have codes.


A New Twist

With all of these components, testing for problems takes on a new twist. In the old days, a road test was always done to see how the vehicle handled. We listened for squeaks, rattles and pops. We also checked to make sure the vehicle stayed straight on the road. Electronics in today’s vehicles now require a great deal more “testing” to verify operation parameters. Radar and cameras have changed the scope of what we must test. In many cases, sensors and cameras must be aligned correctly.

Static testing is done in-shop with targets being placed at specific points for radar systems in blind-spot detection systems. Or, in the case of forward crash warning, target boards are placed in front of the vehicle to align cameras with the vehicle. When a vehicle is stationary, the environment around the computers and sensors that could potentially affect them is not changing.

The white square is a blind-spot detection sensor on a 2017 Hyundai.

Once aligned, sensors and cameras must see correctly and be tested. Dynamic testing is designed to do that. Wikipedia defines dynamic testing (or dynamic analysis) as a term used in software engineering to describe the testing of the dynamic behavior of code. That is, dynamic analysis refers to the examination of the physical response from the system to variables that are not constant and change with time.

When in motion, the environment and parameters change. Sensors must be able to work in both static and dynamic scenarios. Vibration and shocks can change the parameters, too. Not testing the system under, for lack of a better term, “stress,” can lead to problems later. This is why codes can be set at any time, and knowing when and why the code was set is important.


Post-Repair Scan

Now we have to take a look at a post-repair scan of vehicles. Do we scan before a road test or after? Maybe both? We know codes will be set from the repair process. Many times, just disconnecting the battery will set a DTC. During a post-repair scan, we can remove all DTCs after we record them and match to the pre-repair scan.

What does the camera need to see on a test drive for calibration requirements to be met?

Once DTCs are cleared, we’re set, right? Maybe not. We need to test that the repairs are correct or that no other codes will be set while driving. During a test drive, we may need to drive the vehicle much more than around the block. Some systems will not achieve testing parameters until certain speeds or even certain distance requirements are met. In the case of camera recalibrations, speed and a specific number of required indicators must be met. Signs, lines in the road, etc., all may be part of the dynamic test. Since there are variables such as light and weather conditions that can affect the sensors’ detection of objects, the dynamic test while driving is required to ensure that the sensors work under all conditions.

No More Average Road Tests

So we now know the road test is not just a drive around the block and that there is much more involved. This brings up a whole new group of factors for shops.


I want to be sure to clarify that some vehicles will require a simple road test and post-repair scan. Some may require more. When you have systems such as adaptive cruise control, emergency automatic braking, lane departure and crash-avoidance systems, you have to look up procedures to see what will be required. In the process of dynamic testing, here are some things to consider.


The time required for a technician to hook up and set up for a dynamic test may not take very long; it’s a simple hook-up to the OBD port. The drive itself, however, may take time. In some cases, test drives up to 70 miles have to be performed before the computer successfully tests. Note that in some states with distracted driving laws, it may take two technicians to do the test.



Think about what goes through a customer’s mind when they get their vehicle back and there are 40 additional miles on the odometer. What would you think?


Some tests require that the vehicle have a full tank of gas so that the vehicle is at the correct pitch or angle during tests.


Plan your route. The vehicle may need to drive north/south routes so as to avoid driving into the sun while testing. Be sure the route has all the parameters needed, such as signs and lines on the road. Failure to have all these parameters can be the difference between a test being successful or unsuccessful. Vehicles may need to maintain highway speeds for up to 10 minutes for completion of the dynamic test, too.



Weather can play a big role in testing. Rain, snow and clouds can have an impact on testing, as these factors or lighting conditions could affect the sensors.


Not every scan tool can do static or dynamic testing. On newer vehicles, a factory tool may be required. Whether you scan in-house or sublet it out, be sure the tools are right for the job. Scanning is not the same as static testing or dynamic testing. Scanning involves the reading of DTCs and functioning of the circuits. Recalibration is the aiming of sensors with static tests, dynamic tests or both.


Obviously, the advanced cameras and systems can work in many challenging environments. During testing, these variables must be limited to calibrate the systems. You cannot calibrate or test with too many variables affecting the outcome because then you won’t know why the test failed. For example, did the test fail due to bad sensors or was it raining?

Good Practices

When an agreement is made and the car is dropped off for repairs, be sure to inform the customer that the vehicle may require dynamic testing. Explain that the vehicle may be driven on the highway for periods of time to verify that all components are operating. Let the customer know the route they may see the vehicle on so they don’t need to call you and ask why there is someone driving their vehicle down the road. Simple communication can save you from an unhappy customer.



To simply call the drive at completion a road test does not do it justice. Dynamic testing is so much more.

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