FieldBench

Goodman

GMVM97

Furnace · ComfortBridge · modulating · 97% AFUE

Modulating ComfortBridge 97% furnace. Badge twin of Amana AMVM97. Same E / b / d display language as GMVC96, but the gas valve is modulating (percent capacity), not two discrete stages. Do not apply Ht1/Ht2 staging tests.

Not GMVC96 (two-stage ComfortBridge — Ht1/Ht2, two solenoids). Not GR9T96 (9-speed 24V). Not GMEC96 (CT two-stage). The cabinet and triple 7-seg look like a GMVC96 until you see the modulating valve and the percent request.

Walk this in Diagnose

This plate

Input / AFUE
Up to 97–98% class · modulating heat
Valve
Modulating gas valve — percent fire, not W1/W2 solenoids
Inducer
Variable inducer tracking firing rate · draft prove is rate-based
Blower
Communicating variable-speed ECM (14-pin serial)
Control
ComfortBridge IFC · triple 7-segment + shared-data card
Tstat
ComfortBridge communicating preferred · 24V fallback is a coarse heat call, not true modulation
Sister SKU
GCVM97 · Amana AMVM97 same IFC family

This board

ComfortBridge IFC · modulating · three 7-segment digits

  • Status words (idle, Ht, CF, CL1) are not faults. Ht here is a heat-run status, not GMVC96 Ht1/Ht2 staging.
  • Same E / b / d alphabet as GMVC96. Meanings below are rewritten for a modulating prove — do not import two-stage solenoid steps.
  • Shared-data card holds this cabinet’s modulating tables. A GMVC96 two-stage card will not satisfy this IFC (d4).
  • Learn / menu buttons step CFM, heat setup, and last faults. A setup screen is not a lockout.

Sequence

  1. Call. Communicating thermostat requests a firing rate (percent), not W1 then W2. On 24V fallback the IFC runs a coarse heat routine — you lose true modulation.
  2. Low-rate prove. Inducer comes up to the minimum rate. The low-rate pressure path must close before any fire (E1 if already closed at idle, E2 if it never closes). This is not ‘stage 1 of 2.’
  3. HSI / modulate. Nitride warm-up, then the modulating valve opens to light-off rate and ramps toward the request. Failures stack to E0. Weak µA at low percent is E6 — common on this valve.
  4. High-rate prove. As capacity climbs, the high-rate pressure path must close (E9 if it never does, E8 if it was already closed at a low rate). The inducer is tracking the valve, not jumping a discrete high tap.
  5. Blower. Serial ECM CFM tracks the firing rate from the IFC tables. No heat taps. A GR9T96 9-speed or GMEC CT motor will not run here.
  6. Satisfied. Valve toward closed, post-purge. Unexpected flame with the modulator shut → E4.

Faults on this IFC

  • idle / Ht / CF / CL1

    Status, not a fault

    info

    Normal run states. idle = standby. Ht = heat running (a rate, not Ht1 vs Ht2). CF = continuous fan. CL1 = low cool.

    • Do not replace the board because it says idle or Ht.
    • A communicating request sitting at idle is bus / fallback, not a bad modulator.
    • There is no Ht2 to wait for. If capacity will not climb, look at high-rate prove (E8/E9) and the valve, not a W2 wire.
  • E0

    Retry lockout

    lockout

    Light-off or flame-loss retries exceeded at the commanded rate. Three-try-class lockout on this IFC family.

    • Watch light-off at the minimum rate, not a two-stage ‘high fire trial.’
    • Manifold at light-off vs the modulating plate. A valve that never leaves closed looks like E0 forever.
    • Rod, ground, HSI. Do not keep resetting.
  • E1

    Low-rate PS stuck closed

    lockout

    Low-rate pressure switch is made with the inducer at idle. Same letter as GMVC96 E1 — prove is at minimum rate, not ‘low fire stage 1.’

    • Unplug the low-rate switch. Code change = welded switch or water in the hose.
    • Inducer must be off / idle for this code to be honest. A modulator that never shuts the inducer down is a different problem.
  • E2

    Low-rate PS open

    lockout

    Inducer at minimum rate, low-rate switch will not close. No light-off until this proves.

    • Inducer spinning at the light-off rate? 120 VAC / commanded speed.
    • Trap, collector, PVC. A drowned 97% secondary will not prove at any percent.
    • Hose on the low-rate tap. Communicating CFM does not create draft.
  • E3

    Limit / rollout

    warn

    Limit or rollout string opened while modulating. VS blower should have been tracking rate — if the limit still opens, static, overfire at high percent, or rollout.

    • IFC heat CFM vs TES. Filter, coil, return.
    • Which switch is open? Limit = airflow / high-percent overfire. Rollout = exchanger / burners — hazard, manual reset.
    • Clock input at the rate it tripped. A stuck-high modulator overfires like a two-stage valve welded on high.
  • E4

    Unexpected flame

    hazard

    Rod sees flame with the modulating valve commanded shut.

    • Shut the gas cock. If flame stays, leaking modulator — replace, do not drive it as a test.
    • Rod shorted to ground or IFC flame circuit.
  • E5

    Open fuse

    warn

    IFC automotive fuse is open.

    • 24 V short on leftover W/Y/G, humidifier, EAC, or data pair landed on 24V.
    • Unplug harnesses and replace fuse. Repeat blow = board or valve harness.
  • E6

    Low flame signal

    warn

    Flame present but µA is below threshold. Common at low modulating percent — the rod sees a small flame.

    • Clean rod, burner-box ground. µA should rise as rate climbs; flat µA at every percent is rod/ground, not the valve.
    • Light-off rate too lean (valve / orifice / LP). Do not crank a two-stage manifold chart onto this modulator.
    • Confirm flame at minimum percent before you condemn the IFC.
  • E7

    Igniter / ground

    lockout

    Igniter circuit or flame-sense ground failed the command.

    • Igniter ohms and 120 VAC during warm-up. Cracked nitride.
    • Ground screw at the burner box. E7 is HSI/ground — b0 is the blower.
  • E8

    High-rate PS stuck closed

    lockout

    High-rate pressure switch is made while the inducer is still at a low rate. Not ‘high-fire solenoid stuck.’

    • Second switch. Water in the hose or a welded high-rate PS.
    • Inducer actually at low rate? If the inducer is already high with a low request, the IFC/valve ramp is the fault, not E8 physics.
  • E9

    High-rate PS open

    lockout

    Capacity is climbing, inducer is up, high-rate switch never closes. Comfort complaint: ‘it never goes above 40%.’

    • Does the inducer actually accelerate with the percent request? No → IFC / inducer. Yes + E9 → high-rate hose / switch / vent.
    • High-rate hose on its own tap. A tee with the low-rate switch is a first-install miss.
    • Vent that proved at light-off can still fail at 80–100% on a 100–120 kBtu cabinet.
  • EA

    Line polarity / ground

    lockout

    L1/N reversed or chassis ground missing. Modulation and flame sense both suffer.

    • Hot and neutral at the IFC.
    • Burner box to IFC ground screw.
  • b0

    ECM not running

    lockout

    IFC commanded the serial blower and it did not run. Same motor family as GMVC96 — still not a tap motor.

    • 14-pin seated at motor and IFC.
    • Line voltage, wheel free. A 9-speed or CT motor in this cabinet will sit on b0 forever.
  • b1

    ECM comms lost

    lockout

    Serial link to the indoor blower dropped. Motor serial — not the ComfortBridge thermostat pair.

    • 14-pin continuity and rub-through at the blower deck.
    • Reseat motor module and IFC before replacing both.
  • b2

    HP mismatch vs shared data

    lockout

    Motor horsepower does not match the modulating cabinet’s memory card.

    • Motor HP stamp vs this GMVM97 size and the card on the IFC.
    • A GMVC96 two-stage motor/card mix throws b2/d4 even when the wheel would spin.
  • d0

    No shared data / missing memory card

    lockout

    IFC cannot read the furnace identity card. Classic after an IFC swap when the card stayed on the old board.

    • Move the card from the failed IFC onto the replacement. That card is the modulating cabinet.
    • A blank board with no card will not run. Do not borrow a GMVC96 two-stage card to ‘get heat.’
  • d4

    Invalid memory card

    lockout

    Card present but wrong family or unreadable. A two-stage GMVC96 card is invalid on a GMVM97.

    • OEM card for this exact GMVM97 / GCVM97 size.
    • Reseat. d4 after a ‘universal ComfortBridge’ card is the card, not the valve.

Workflows

Confirm it is modulating, not GMVC96

First minute. Triple 7-seg in a Goodman 97% cabinet.

  1. Data plate: GMVM97 / GCVM97. Valve is a modulator (percent), not two solenoids.
  2. Communicating request is a rate. There is no W2 high-fire click to wait for.
  3. If the plate says GMVC96, use that chart — two-stage ComfortBridge, different valve, different shared-data card.
  4. 24V fallback on this IFC is heat-on, not true modulation. A job ‘converted’ off a communicating stat will never stage like the selling sheet.

No heat / will not modulate up

Idle with a call, E0/E2 at light-off, or stuck at low percent with E9.

  1. Photograph the triple display and the stat rate request.
  2. Communicating or 24V fallback? Fallback will not climb through a percent curve.
  3. E2 at light-off: trap, low-rate PS, inducer at minimum rate. Same 96/97% collector drowning as any condensing Goodman.
  4. Lights and sits at low percent + E9: high-rate PS path and inducer acceleration, not a W2 wire.
  5. E6 at low percent: rod/ground first, then light-off rate. Do not apply a two-stage manifold spec.
  6. d0/d4 after a board swap: the modulating card must travel with the cabinet.

Test points

Valve
Modulating operator. Percent fire per communicating request — not two discrete solenoids.
Data pair
ComfortBridge voltage / polarity. Never 24 VAC on the data pins.
Shared-data card
GMVM97 family card. A GMVC96 two-stage card is d4.
Motor harness
14-pin serial ECM. No taps. No CT profile plug.
Flame rod
µA at minimum percent and again at high percent. Must exist at both ends of the curve.

Gotchas

  • Amana AMVM97 is the badge twin. Same chart.
  • GMVC96 looks identical until you read the plate and the valve. Two-stage staging tests will lie on this furnace.
  • 24V W on a modulating ComfortBridge IFC is a fallback heat call. Homeowners who ‘put a regular stat on it’ lose the product.
  • Do not import GR9T96 E8/E9 hose stories onto the wrong motor — the draft physics rhyme, the blower and valve do not.

Related plates

  • amana-amvm97 — Amana badge twin — same modulating ComfortBridge IFC and valve family.
  • goodman-gmvc96 — Two-stage ComfortBridge cousin. Same E/b/d alphabet, discrete Ht1/Ht2, different card and valve.