B0105Sensor Cleaning Air Blower Actuator B Control Relay
- Generic OBD-II code · Body
- Can trigger limp mode
- How the car detects it
- B0105 is the relay fault on the B side of the sensor-cleaning air supply. If B is a compressor rather than a small fan, as in Uber's patent where a compressor charges an accumulator and recharges once pressure drops to roughly 130–140 psi, the relay carries a sizable inrush current, and pitted contacts become the usual weak point. HELLA lists change-over and make relays for motors such as fans and names the checks: dropout voltage, contact drop, coil resistance. AUMOVIO stresses that air keeps a lidar usable in bad weather by blowing off droplets, so a stuck relay shows up first in rain. No carmaker has published B0105 or what B supplies.
- What you may notice
- Blower or compressor B does not start, or will not switch off
- Droplets stay on sensor windows in rain
- Assistance functions drop out when a sensor is reported blocked
- Likely causes
- LikelyContacts of relay B pitted by high motor or compressor inrush current
- PossibleRelay B coil or its suppression diode failed
- RareCorroded relay socket or wrong relay type fitted
- Repair
- Easy · Often possible to do yourself.Typical cost: €20 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.