P0773 Fault Code in Ford: Causes, Symptoms, and Fixes

The PCM/TCM (Powertrain/Transmission Control Module) has detected an electrical fault with Shift Solenoid E, which controls hydraulic circuits that engage/disengage transmission gears. It usually indicates a problem with the solenoid coil circuit (open, short, or high resistance).

Possible Causes

1. Faulty Shift Solenoid E (internal failure or stuck).
2. Wiring issues – damaged, corroded, or shorted harness between TCM and solenoid.
3. Poor electrical connections (loose pins, moisture in connector).
4. Faulty Transmission Control Module (TCM).
5. Low or dirty transmission fluid (causing solenoid overheating/failure).
6. Internal transmission hydraulic blockages.

Symptoms

1. Check Engine Light (CEL) ON.
2. Harsh, delayed, or failed gear shifts.
3. Transmission stuck in limp mode.
4. Poor acceleration or loss of fuel efficiency.
5. Overheating of transmission in severe cases.

Diagnosis Steps

1. Scan for additional transmission-related codes.
2. Inspect transmission fluid (level & condition).
3. Check wiring and connectors at the transmission harness.
4. Perform an ohm test on the shift solenoid (compare with spec).
5. Use a scan tool to command Shift Solenoid E ON/OFF and monitor response.
6. If wiring and solenoid are fine → suspect TCM fault.

Possible Fixes

1. Replace or repair Shift Solenoid E.
2. Repair/replace damaged wiring or connectors.
3. Transmission fluid flush & filter replacement.
4. Reprogram or replace TCM/PCM (if confirmed faulty).
5. In rare cases, internal transmission repair if hydraulic passages are clogged.