Bryant 355MAV Error Code 41: Blower Motor Fault
What Does Code 41 Mean?
Status code 41 on the Bryant 355MAV is a blower motor fault. The control detected that the blower either failed to reach 250 RPM within 30 seconds of being turned on, or lost communication during steady-state operation (caught within about 10 seconds of the signal dropping).
The 355MAV uses a variable-speed ECM blower that exchanges digital data with the control board about speed, torque, and status — unlike an older PSC motor that simply runs when powered. When that communication drops or the motor cannot achieve the commanded speed, the board cannot confirm airflow is adequate to cool the heat exchanger, so it flags the fault.
This is the single-cycle version of code 15 (Blower Motor Lockout). If the fault repeats in two successive heating cycles, the board escalates from code 41 to a code 15 lockout. The most common cause is a failed ECM motor or its integrated control module, which can fail even when the windings are intact. A wiring or connector problem — loose plugs, corroded pins, damaged conductors — that interrupts the digital link is the next most likely cause. Diagnosis needs specialized tools, so it is technician work.
What You'll Notice
- The blower does not run, or runs erratically, during a call for heat
- Little or no warm air reaches the vents even though the burners may light
- The motor hums or clicks but does not spin up to speed
- The status LED flashes code 41 (four short flashes, one long flash)
- If it repeats, the furnace escalates to a code 15 lockout
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Failed ECM blower motor | Most common | ✗ Call a pro → |
| Wiring issue between control and blower motor | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician confirms the ECM motor is receiving both its high-voltage supply and its low-voltage control signal, then checks the digital communication link between the board and the motor module, since a dropped link produces this code even on a healthy motor. Connectors and the harness are inspected for loose or corroded pins.
If power and signal are present but the motor still cannot reach speed, the ECM motor or its module is tested and typically replaced. Because this involves the variable-speed motor and its control circuitry, it is not a homeowner repair.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The blower does not run or runs erratically and the furnace shows code 41
- The motor hums or clicks but will not spin
- The fault keeps recurring and threatens to escalate to a code 15 lockout
- Connectors or wiring to the blower motor look loose, corroded, or damaged
Frequently Asked Questions
Is code 41 the same as code 15 on a Bryant 355MAV?
They are closely related. Code 41 is the single-cycle blower motor fault; if it happens in two consecutive cycles, the board escalates to code 15, a lockout. Both point to the ECM blower failing to reach speed or communicate.
Could code 41 just be a loose wire rather than a bad motor?
Yes. A loose or corroded connector or a damaged wire can interrupt the digital communication between the board and the ECM motor and trigger this code. A technician checks the wiring before condemning the motor itself.
Sources
✓ Verified against manufacturer service manual — March 2026