Ruud U96VA0702317MSA Error Code 68: No Blower Communications
What Does Code 68 Mean?
A code 68 on the Ruud U96VA0702317MSA is a critical fault indicating the IFC control board has lost communication with the ECM (electronically commutated motor) blower. The ECM blower requires a continuous digital data link with the IFC to receive speed commands and operating parameters — when communication fails, the blower cannot run and all furnace operation halts. No heating, cooling, or fan-only modes are available until communication is restored.
When code 68 occurs during a heating call, the gas valve closes immediately, the indoor blower stops, and the induced draft motor runs post-purge at the correct speed before shutting down. After post-purge completes, or immediately if no heating call was active, the furnace remains off until the fault is cleared. The communication failure can occur at any time during operation.
The most common cause is a loose or disconnected wiring connection between the IFC and the blower motor — whether at the IFC connector or at the motor housing connector. The blower harness carries both power and digital communication signals, and a break in either path interrupts the communication link. No line voltage reaching the motor (from a blown overcurrent device or a failed circuit), faulty or corrupted model data on the memory card, or a completely failed ECM motor are additional causes. A technician must check all connections, verify power is reaching the motor, and test the motor electronics.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Disconnected or damaged wiring between control board and blower motor | Most common | ✗ Call a pro → |
| Catastrophic motor failure | Common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician to inspect and reseat all wiring connectors between the IFC and the ECM blower motor — a loose harness connection is the most common and easiest fix for code 68
- If connections are secure, the technician should verify line voltage is reaching the motor, check the PFC choke integrity, confirm model data is valid, and test or replace the ECM motor if it has internally failed
✓ Verified against manufacturer service manual — March 2026