Can a radar sensor be tested before replacing it? My 2018 Prius hit the car in front of it in a car wash. The emblem is broken. The radar cruise control mostly works, but intermittently gives a warning that says “Clean radar sensor.” It has happened 3 times. Today I noticed that it happened when I went around a curve. I am not sure the sensor needs to be replaced, but that is what the body shop will do. Is there any way to test the sensor to be sure it is defective? Can I just replace the emblem without replacing the sensor? Will druise work with a defective sensor if I just use it in conventional cruise control mode?
If it’s broken, the emblem assembly (discussed in my October 2017 posting) should be replaced. The only other parts that would have to be replaced at the same time as the emblem assembly are the two spring nuts, part number 90183-06031. If a new emblem assembly doesn’t fix the problem, the radar beam axis adjustment procedure, described in the Repair Manual (more info) and briefly in my February 2018 and March 2019 postings, should be done. A new millimeter wave radar sensor assembly (part number 88210-07010) would be the last resort, and probably isn’t needed, if there are no messages or warning lights other than “Clean Radar Sensor.” The sensor assembly has a built-in self-test feature, and the adjustment procedure is effectively a further test. Parts catalog references: Figure 75-01, Emblem & Name Plate (Exterior & Interior) Figure 84-08, Cruise Control (Auto Drive)
If that's all that's broken, that's probably all you need to replace. The sensor is well behind it. Edit to add. Just to be sure, I went out and removed the plastic trim covering that area and it looks like the sensor is about an inch behind the emblem, held on by brackets.
