What this code means
B1241 may mean the HVAC control system is seeing blower motor feedback that does not match the requested blower operation.
What the vehicle may do
- The blower may not run.
- Airflow may be weak or inconsistent.
- Fan speed may not respond normally to the climate control setting.
Possible fault areas
- Possible blower power feed, ignition feed, or ground circuit issue.
- Possible blower relay output or blower motor circuit issue.
- Possible power transistor control circuit issue.
- Possible blower motor issue.
- Possible climate control unit issue after the other inspection items check normal.
Diagnostic path
Opening and code meaning
For B1241 on this 2020 to 2025 Honda CR-V Hybrid, we’re dealing with a blower motor circuit problem in the HVAC system. In plain terms, the climate control unit may be asking for a certain blower command and not seeing the blower feedback line up with that request. The driver may notice weak airflow, no blower operation, or blower behavior that doesn’t match the commanded fan speed. Broadly, the fault area can include the blower power feed, ignition feed, grounds, relay output, blower motor control wiring, the blower motor itself, the power transistor circuit, or, after the rest of the checks pass, the climate control unit.
Set up the diagnosis and confirm the code
Before you troubleshoot, slow down and follow the basic HVAC troubleshooting approach so you are not guessing at the blower circuit. Start by turning the vehicle to the ON mode. Then run the HVAC self-diagnostic with the HDS or through the climate control unit. That confirms you’re chasing the active B1241 path before you start breaking into the blower circuit.
First circuit group: main feed, ignition feed, ground, and relay output
Next, set up for the first circuit inspection by disconnecting the blower motor relay and disconnecting the 2P blower motor connector. With IG Mode OFF, check the +B_HTR_MTR circuit. Normal is 12 V battery voltage. Then turn IG Mode ON and check the IG2_OPTION circuit. That should also show 12 V battery voltage. Turn IG Mode OFF again and check the ground side for an open; normal is less than 1 Ω. Still with IG Mode OFF, check the BLOWER_MTR, BLW-RLY output, for an open; normal is less than 1 Ω. If any part of this group is abnormal, treat it as a circuit problem. If the power supply portion is abnormal, continue with the power supply checks to locate where that feed is failing.
BLW-M circuit inspection
After that, move to the BLW-M circuit. Disconnect the 2P blower motor connector and the 4P power transistor connector. With IG Mode OFF, check BLW-M for an open. Normal is less than 1 Ω. Then check BLW-M for a short to ground with IG Mode OFF. Normal is more than 1 MΩ. If either result is outside normal, the problem is in that circuit.
Power transistor to climate control unit circuits
Now inspect the ground, BLW-V, and BLW-G circuits between the power transistor side and the climate control unit side. Disconnect the 4P power transistor connector and climate control unit connector B, the 24P connector. With IG Mode OFF, check the ground circuit for an open; normal is less than 1 Ω. Check BLW-V for an open; normal is less than 1 Ω. Check BLW-G for an open; normal is less than 1 Ω. Then check BLW-V and BLW-G for shorts to ground with IG Mode OFF. Each one should be more than 1 MΩ. Any abnormal result here points back to a circuit problem in that leg.
Blower motor functional check
Once the external circuit checks are normal, perform the blower motor functional inspection. The setup is the 4P power transistor connector disconnected. Connect power transistor connector terminal No. 1 to body ground with a jumper wire, then turn the vehicle to the ON mode. The expected result is that the blower motor runs. This functional check can be used earlier as a quick check, but if it fails, you still need to go back through the individual circuit inspections to find which item failed. If the blower motor does not run in this check, the problem is with the blower motor.
Climate control unit decision point
If the circuit inspections are normal and the blower motor functional inspection is normal, the remaining fault area is the climate control unit. Do not jump to that conclusion early; it comes after the wiring, power, ground, control circuits, and blower motor have all checked normal.
Takeaway and CTA
The clean path for B1241 is to confirm the HVAC code, prove the blower feeds and grounds, prove the BLW-M, BLW-V, and BLW-G circuits, then confirm blower operation before calling the climate control unit. Takeaway: keep this diagnosis circuit-based and let each test narrow the fault area. For more diagnostic training, visit stepdiagnostics.com.
Final check
B1241 is often best approached as a step-by-step electrical circuit diagnosis, not as a parts guess.
For more guided automotive diagnostics, visit STEP Diagnostics.
