B2101low severityBody
Daytime Running Light Module Circuit
on 2018 Mazda Mazda3 2.5L I4 · FWD
What this code means
Malfunction in the daytime running light (DRL) module or circuit.
Symptoms
- DRLs not illuminating
- DRLs always on even with headlights on
- DRL brightness incorrect
- DRL warning message on display
Common causes
- Faulty DRL module
- Burnt out DRL bulb/LED
- Wiring issue
- BCM DRL output fault
- Light sensor input error
Diagnostic steps
- Check DRL bulbs/LEDs
- Test DRL module power and ground
- Inspect wiring
- Scan BCM for DRL codes
- Test light sensor input
Repair notes
Replace DRL bulbs/LEDs or DRL control module.
Other Body codes on this vehicle
B0001
Driver Frontal Stage 1 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0005
Driver Knee Airbag Deployment Circuit
B0006
Passenger Knee Airbag Deployment Circuit
B0007
Rear Left Side Airbag Deployment Circuit
B0008
Rear Right Side Airbag Deployment Circuit
B0009
Rear Center Airbag Deployment Circuit
B0010
Driver Side Airbag Deployment