P0788 Code: Shift Timing Solenoid A Circuit High
🟠 Moderate severity · drivable
Drivable, but the transmission may shift harshly or fail to shift; avoid long trips until repaired.
What P0788 means
The engine computer sees voltage from the shift timing solenoid A circuit that is too high, usually from a short to power or a failed solenoid. The transmission may not shift gears properly while the fault is present.
Symptoms
- Check engine light is on
- Harsh or erratic gear shifts
- Transmission stuck in gear
- Transmission slipping
- Reduced fuel economy
Common causes
- most common: Wiring shorted to power in the solenoid circuit
- common: Faulty shift timing solenoid A
- less common: Corroded or damaged connector
- rare: Faulty transmission control module
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect and repair wiring shorted to power | Yes | $50–150 |
| Replace shift timing solenoid A | Mechanic | $150–400 |
| Replace the transmission control module if it is faulty | Mechanic | $500–1200 |
Frequently asked questions
Can I drive with a P0788 code?
Yes, but the transmission may shift poorly or stop shifting altogether. Keep driving gentle and get it fixed soon.
What does a "high" circuit mean for P0788?
The computer sees voltage above normal, usually from a wire shorted to battery power or a failed solenoid.
How much does it cost to fix P0788?
Most fixes are $150–$400 for a solenoid replacement; a wiring repair is usually $50–$150.
Related codes
P0785
P0785 Code: Shift Timing Solenoid A Circuit Malfunction
P0787P0787 Code: Shift Timing Solenoid A Circuit Low
P0700P0700 Code: Transmission Control System Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.