What it means
This code identifies a fault associated with Sensor Cleaning Air Blower Actuator A Control Relay. The code alone does not specify the failure mode.
How it works
Sensor Cleaning Air Blower Actuator A Control Relay switches or supplies power for blower actuator A. B0104 identifies a fault associated with this relay function; the code alone does not establish whether the relay, its control wiring, or its supply is responsible.
Common causes
Most likely first.
- Faulty relay
- Open or shorted wiring
- Loose or corroded connector
- Blown fuse
Symptoms
- Sensor or camera visibility warning
- Reduced sensor function
- Warning light or message
How to diagnose it
- Scan the relevant module for B0104 and related blower or relay codes, and review freeze-frame or live data for the actuator A relay command.
- Use the wiring diagram to identify the actuator A control relay and inspect its connector, socket, and nearby wiring for corrosion, heat damage, looseness, or chafing.
- Check the relay's fuse and supply circuit against the vehicle wiring diagram and manufacturer's specification.
- Test the relay control and switched circuits using the manufacturer's procedure, checking for opens, shorts, and poor connections.
- If the relay is serviceable and testing permits, compare its operation with a known-good equivalent specified for that circuit, or test it to the manufacturer's specification.
Common fixes
- Clean and secure the actuator A relay connector or socket if contact is poor.
- Repair damaged relay control or supply wiring.
- Replace a failed fuse after correcting any short or overload.
- Replace the actuator A control relay if testing confirms it fails to switch correctly.
- Repair the controlling module only if its relay command is confirmed faulty.
Can I keep driving?
You can generally drive, but blower actuator A may not run, allowing its sensor or camera to become obscured. Keep that area clean and avoid relying on related driver-assistance features when visibility is reduced.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.