Goodman furnace code b4: Motor Trips
Professional repair
What does b4 mean on a Goodman furnace? The ECM motor sensed a loss of control or became overloaded and shut down.
Before you touch anything: the six signs that mean stop troubleshooting and call a pro →
Motor and load diagnosis. DIY part cost: $400–800 — a pro visit for this class of fault typically runs $150–350.
What causes it (in order of likelihood)
- Motor overload / control loss TECH
Parts referenced by this code
Always match parts against your model's parts list — part numbers vary within a series.
Questions about this code
What does b4 mean on a Goodman furnace?
The ECM motor sensed a loss of control or became overloaded and shut down.
How do I fix Goodman furnace code b4?
There's no safe homeowner fix; motor and load diagnosis is technician work. Note when it happens and what the furnace was doing.
How much does it cost to fix Goodman furnace code b4?
Cost depends on what caused the overload or loss of control. A technician's motor and load diagnosis is needed before you can get a repair quote.
Applies to
GMVC96 · GCVC96
Different Goodman generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.
Same control platform, same code: Amana furnace code b4
Verified against Goodman GMVC96/GCVC96 Service Manual, p.45
Last verified 2026-07-06 · page updated 2026-10-03 · how we verify
Other Goodman furnace codes
These links include other Goodman model families. Code meanings can change by model and control board, so confirm your model and service manual before using a definition.
| Pattern | Meaning |
|---|---|
| b3display b3 | ECM Motor in a Limiting Condition (b3) |
| ONdisplay ON | Display Reads ON — Normal |
| b2display b2 | Motor Horsepower Mismatch (b2) |
| Id Ldisplay Id L | IdL: Normal Standby |