P0803 — Shift/Timing Solenoid High
Drive with caution — fix soon.
What P0803 means
This code means the control module detected a high voltage or open circuit condition in the shift/timing solenoid circuit. It's commonly caused by an open or broken wire, corroded or disconnected connectors, or a failed solenoid, and sometimes a control module fault. Repairs usually involve testing and repairing the wiring, cleaning connections, or replacing the solenoid.
Common symptoms
- Check engine light is on
- Harsh, delayed, or erratic shifting
- Transmission may enter limp mode
- Slipping or inconsistent gear changes
- Reduced fuel economy in some cases
Common causes
- Open circuit or high voltage in the solenoid wiring
- Broken, corroded, or disconnected connectors
- Damaged or chafed wiring harness
- Failing shift/timing solenoid
- Faulty transmission control module
Typical repair cost
$100 – $900
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0803 code?
Often yes for the short term, particularly if the car still shifts properly. Since it's an electrical fault, though, it can lead to erratic shifting or limp mode, so it's best to have it diagnosed soon.
How much does it cost to fix a P0803 code?
It's often relatively affordable. Repairing an open wire or corroded connector may cost little, while replacing the solenoid can run a few hundred dollars depending on labor and access.
Is a P0803 code serious?
It's usually moderate. The vehicle often still drives, but leaving an electrical fault unaddressed can cause shifting problems or limp mode, so it's worth repairing promptly.
What does 'solenoid high' mean in a P0803 code?
It means the circuit voltage is higher than expected or the circuit is open, often from a broken wire or loose connector. Diagnosis usually starts by checking the wiring and connections before replacing the solenoid.