P0787 Code: Shift Timing Solenoid A Circuit Low
🟠 Moderate severity · drivable
Drivable, but shifting may be harsh or the transmission may stick in gear; keep trips short.
What P0787 means
The engine computer reads the voltage from shift timing solenoid A's circuit as too low. That usually means a short to ground, an open wire, or a failed solenoid, so the transmission may not shift into the right gear.
Symptoms
- Check engine light is on
- Harsh or delayed shifts
- Transmission stuck in one gear
- Transmission slipping
- Poor fuel economy
Common causes
- most common: Faulty shift timing solenoid A
- common: Short or open wiring in the solenoid circuit
- common: Corroded or loose connector terminals
- rare: Faulty transmission control module
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Inspect and repair the solenoid wiring and connector | Yes | $50–150 |
| Check and top up the transmission fluid | Yes | $20–60 |
| Replace shift timing solenoid A | Mechanic | $150–400 |
Frequently asked questions
Can I drive with a P0787 code?
Yes, but the transmission may shift hard or stay in one gear. Drive gently and get it checked soon.
What does a "low" circuit mean for P0787?
It means the computer sees voltage below normal, often from a short to ground, a broken wire, or a failed solenoid.
How much does a P0787 repair cost?
A wiring repair is about $50–$150, and replacing the solenoid is usually $150–$400 with labor.
Related codes
P0785
P0785 Code: Shift Timing Solenoid A Circuit Malfunction
P0788P0788 Code: Shift Timing Solenoid A Circuit High
P0700P0700 Code: Transmission Control System Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.