GOODMAN DIAGNOSTIC REFERENCE MODULATING FURNACE (GMVM97) — DUAL 7-SEGMENT DISPLAY DOC GOODMAN-GMVM97-B4

Goodman furnace: Blower Current Trip or Lost Rotor (b4)

Q: What does b4 mean on a Goodman GMVM97 furnace?

Blower Current Trip or Lost Rotor (b4). The blower tripped on overcurrent or lost rotor sync — abnormal motor loading or a sudden change in load.

b4 YOUR LIGHT: DISPLAY CODE B4 — MATCH IT ABOVE

Professional repair

What does b4 mean on a Goodman GMVM97 furnace? The blower tripped on overcurrent or lost rotor sync — abnormal motor loading or a sudden change in load.

See what causes this code ↓ Get repair quotes near you

Motor + wheel inspection. 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 / obstruction TECH

Parts referenced by this code

ECM Blower Motor

$400–800 · Model-specific

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Always match parts against your model's parts list — part numbers vary within a series.

Applies to

GMVM97

Different Goodman generations use different code maps. If your series isn't listed, don't assume this meaning — check your blower-door label.

Verified against Goodman GMVM97 Service Manual, p.67/68

Last verified 2026-07-06 · how we verify

Related Goodman fault codes

These codes use the same modulating furnace (gmvm97) — dual 7-segment display system.

Pattern	Meaning
b3	Blower in Power / Temperature / Speed Limit (b3)
b5	Blower Locked Rotor (b5)
b2	Blower Horsepower Mismatch (b2)
b6	Blower Voltage or Temperature Trip (b6)

See all Goodman furnace fault codes →