b7 Blower motor missing parameters

What the control is telling you

The motor does not have enough data to run properly, or it failed to start 40 times in a row. Furnace will not run. ComfortNet thermostat shows MOTOR PARAMS b7.

Applies to: GMVC95/AMVC95 upflow and *CVC9 counterflow two-stage furnaces

Likely causes

• Problem with the furnace control or its shared data
• Locked rotor

Test and repair steps

1. Safety turn power off before working on the control or wiring.
2. Check the control has the correct shared data for this model (see d0 / d4). Reload with the correct memory card if needed.
3. Check for a locked rotor (see b5).
4. Replace failed parts with the correct replacements.

Settings for these units

• Normal status displays (7-segment) · Goodman/Amana GM9S96/AM9S96
• Normal status displays (7-segment) · Goodman/Amana GM9S80/AM9S80
• Normal status displays (7-segment) · Goodman/Amana GM9C96/AM9C96
• Minimum recommended filter size · Goodman/Amana GM9C96/AM9C96

Models that show this code

10 models in Goodman/Amana *MVC95/*CVC9 two-stage ComfortNet

Other codes on the same units

• b3 Blower motor limiting (power, temperature or speed)
• b4 Blower motor trip (lost rotor control or high current)
• b5 Blower motor locked rotor
• b6 Blower motor over/under voltage or over temperature
• b9 Low indoor airflow
• C1 Low-stage cooling
• C2 High-stage cooling
• d0 No shared data on the control