P0903
Clutch A Actuator Control Circuit High
Automated clutch actuator
Generic OBD-II
Medium
What it means
P0903 means the control circuit for clutch actuator "A" is reading a high voltage — typically a wiring short-to-power, an open, or a failed actuator. On automated-manual and dual-clutch transmissions this actuator engages the clutch, so a fault can leave the car shifting poorly, stuck in a gear, or unable to move. The engine still starts, but the transmission side needs prompt attention.
Medium
Can I keep driving? The engine starts, but the automated clutch may not operate — the car can be stuck in gear or unable to move, so be ready to stop safely and repair promptly.
Common symptoms
What you'll notice
- Check-engine light on
- Poor shifting or failure to shift
- Transmission stuck in one gear or won't engage
- Reduced performance or limp mode
Common causes
Most likely first
- Faulty clutch actuator (motor or solenoid)Likely
- Wiring shorted to voltage or open in the actuator circuit (signal high)Common
- Loose or corroded connectorsCommon
- Failed transmission control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the clutch actuator connector and wiring for shorts to power or opens.
- Measure the actuator control circuit voltage and resistance against specification.
- Test the actuator itself for correct operation.
- Replace the clutch actuator if it fails; repair the wiring as needed.
- If the circuit and actuator are good, diagnose the TCM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0903?+
Only cautiously. On automated-manual and dual-clutch transmissions a clutch actuator fault can leave the car stuck in gear or unable to move, so plan for a repair rather than a long trip.
Can I just clear P0903?+
It clears, but a shorted circuit or failed actuator brings it straight back until repaired.
Related codes
Often seen with P0903
Read & clear P0903 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX