B0109 code meaning
LIDAR Washer Actuator D
What B0109 means
B0109 ends the lidar washer group with actuator D; the next codes, B010A onward, move on to camera washers. Four lidar circuits match fleets built for driverless service: Kautex fits two complete Allegro cleaning and clearing systems to every Zoox robotaxi, combining water and air for cameras and lidars. On Ford’s self-driving test cars, nozzles next to each lens spray washer fluid on demand, and the roof tiara that carries cameras and lidar adds an air curtain. In Ford's US10569746B2 the computer can even leave autonomous mode while a lidar window is too opaque. Nothing public tells which unit is D, and no carmaker documents B0109. A failed actuator D usually shows as one lidar staying dirty while the others clean normally.
B0109 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0109
- One lidar remains dirty while the other sensors are cleaned
- Vehicle limits or ends automated driving
Common causes of B0109
- Most likelyPump or valve D for the fourth lidar nozzle defective
- PossibleHose to lidar D kinked or pulled off, so the actuator runs dry or overloaded
- Less likelyOpen or shorted wire to actuator D
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Lidar washer actuator dActuator wiringObject detection maintenance module a
What each part of B0109 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 09 | The exact fault in that area. |
What to do next
- Note B0109 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0109
What does B0109 mean?
B0109 means "LIDAR Washer Actuator D". B0109 ends the lidar washer group with actuator D; the next codes, B010A onward, move on to camera washers. It is a generic code, so it means the same on every make.
Is it safe to drive with B0109?
Drive gently and only to a workshop. With B0109 the car can go into limp mode (reduced power) to protect itself.
Will B0109 fail an emissions test?
B0109 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0109 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0109 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.