Front Radar Sensor
The forward-looking radar behind the grille, badge or bumper skin that measures the distance and closing speed of what is ahead.
Radar is used rather than a camera for one reason: it measures speed directly. The returned wave is shifted in frequency by the target's motion, so closing speed is measured rather than inferred from how a shape grows between frames — and it works in rain, fog, spray and darkness that leave a camera useless. What it is poor at is telling one object from another, which is why cars carry both.
Some vehicles have two, and the letters in the codes reflect it. A single long-range unit sees far but narrowly; a second, wider unit exists to catch what is about to cut in from the side, and a vehicle may also carry corner radars for blind spot and cross-traffic warnings.
Aim is everything, and it is measured in fractions of a degree. A unit pointing very slightly off looks at the next lane at distance, which is how a car comes to brake for nothing or ignore something real. So it is calibrated after any disturbance — and a parking knock that leaves no visible mark is enough to require it.
Its ordinary enemies are not electrical. Packed snow, ice, mud and thick road film block it; so do aftermarket badges, light bars and thick number plate surrounds. A blocked radar usually says so and clears when cleaned, which is a useful distinction from a radar that has gone silent on the network.
Also known as: radar sensor, cruise control radar, distance sensor, ACC radar, front radar module
Referenced by 3 codes
Codes involving this component (3)
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- Seat Control Module 28
- Fuel Filler Door 26
- Impact Sensor 26
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- Steering Column Control Module 21
- Stop-Start Switch 20
- Door Switch 17
- Door Window Motor 10
- Air Conditioning Refrigerant Expansion Valve 7
- Instrument Cluster 6
- Moveable Roof Control Module 5
- Mirror Control Module 5
- Pedestrian Alert Module 3
- Park Assist Module 3
- Remote Function Actuation Module 3
- Automated Driving System Control Module 2
- Seat Control Switch Module 2
- Speech Recognition Module 2
- Folding Top Control Module 1
- Heated Steering Wheel Module 1
- Haptic Control Module 1
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