I was called to a shop for a 2017 Honda CRV (Figure 1) that was recently involved in a front end collision. The shop was concerned about the Collision Avoidance & Lane Keeping Assist System icons being illuminated on the instrument cluster (Figure 2). The shop owner was well educated in the constant advancement in technology of today's vehicles. He believed that it had something to do with the new radar control assembly that he had replaced behind the front grill. He felt that there was probably some type of procedure to program or calibrate the new assembly he had just replaced. He went as far as leaving the front of the vehicle dismantled for easier access to the radar control unit even the manufacture had a removable cover within the grille. This he did just in case there were other issues with the radar assembly wiring.
The radar assemblies on many of the new cars are becoming a common feature as Collision Avoidance systems get cheaper to produce and have now become a staple for vehicle safety. The systems each manufacturer uses all have the same goals involved. They all try to maintain a safe distance from the vehicle in front of the radar assembly and work through a network of other onboard controllers such as the Engine & Antilock Brakes for vehicle acceleration and deceleration thus avoiding an unwanted collision. Once the system is activated through the Advanced Cruise Control system the driver can select the vehicle speed and car length distance to maintain. The brake pedal can be applied manually at any time to override the system to shut it down.
There are some systems that will also incorporate Lane Keep Assist that will work with a front facing camera in the rear view mirror and the Electronic Power Steering such on this vehicle. The LKAS system will actually see the lines in the roadway with the Front Facing Camera and keep you in your lane by using the Steering Angle Sensor value from the ABS or EPS systems and command the EPS to steer the vehicle within the lane even on curved roadway. So basically it becomes a self-driving vehicle that will slow down / accelerate and steer the vehicle without your assistance at cruising speeds. Technology has certainly come a long way and it's only the beginning.
What makes these radar calls from a shop so challenging is that every manufacturer has a different protocol to tackle the task of either programming or calibrating the system. This can even change from Year to Model as well, while each manufacture keeps tweaking the systems to make them even better than what they already are. The radar systems all require vertical and horizontal adjustments once they have been either replaced or tampered with and some may even require software installation or updates. These procedures may require a static or dynamic calibration using a radar target or the roadway. This depends on the manufacture. Most manufacturers will have their own specific tools to perform these tasks and sometimes these tools can be cross breed to work with multiple manufactures. It can get very costly to buy every tool for all the manufacturers.
When I placed my OEM scan tool on the vehicle I selected the Adaptive Cruise Control Module and selected the trouble code menu. There was a code P2583-76 that stated a "Temporary Stop of Integrated Driver Support System" (Figure 3). This was because the ACC system needed the Millimeter Wave Radar system calibrated. This particular system consisted of a radar assembly located at the center of the radiator support center lined where the Honda emblem would be located (Figure 4). The radar assembly had 2 adjusting screws. The top left was for the Horizontal adjustment and if adjusted clockwise it would increase degree measurements. The bottom right was for the Vertical adjustment and if it was also adjusted clockwise it would increase degree measurements (Figure 5).
Prior to attempting to perform the Vertical adjustment the vehicle must meet conditions that will affect the outcome if not addressed properly. The vehicle must be repaired back to factory specifications making sure the radiator support and all brackets involved in holding the radar assembly are true. If the radar assembly is damaged in any way it must be replaced with a whole new assembly. The vehicle must be on a level surface and have proper curb height and properly inflated tires. Once this is done, you will have to use a proper bubble gauge recommended by the manufacturer (Figure 6) to vertically align the radar unit using the lower right screw. The adjusting tool used is usually a 3.5mm reversed hex driver and this may have to be purchased as well if you don't have one.