Plausibility fault in the drive circuit of the reverse shift actuator of an automated manual gearbox, the actuator that moves the shift mechanism opposite to the forward direction. The circuit is neither open nor shorted, but current, voltage or the resulting shift movement do not match the command. No manufacturer documents this code publicly. A Hyundai/Kia patent detects jammed shift actuators from rising motor current, and a ZF patent shows double-acting shift cylinders with one solenoid valve per chamber, so each direction can be judged on its own. CARB requires functional checks on such outputs. P0924, P0926 and P0927 are the clear electrical faults, P0921 the forward direction, P0919 the missed target. Shifts in this direction become slow or fail.
Medium severity. Can I keep driving?Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
Symptoms
- Transmission warning light on
- Slow, harsh or aborted gear changes in one direction
- Fallback mode with fewer available gears
Most likely causes
- Sticking shift valve, worn shift motor or stiff shift linkage
- Solenoid or motor resistance out of specification
- Increased contact resistance in connector or wiring
- Insufficient hydraulic pressure on hydraulic units
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
- It affects emissions.
What each character of P0925 means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 9: Transmission
- 25: Specific fault in that system
Frequently asked questions
Can I keep driving with code P0925?
Drive as little as possible and gently. If the transmission slips or stays in one gear, go slowly to a repair shop or call for a tow truck.
What causes code P0925?
The most common causes are: sticking shift valve, worn shift motor or stiff shift linkage; solenoid or motor resistance out of specification; increased contact resistance in connector or wiring.
Related codes
- P0924Gear Shift Reverse Actuator Circuit/Open
- P0926Gear Shift Reverse Actuator Circuit Low
- P0927Gear Shift Reverse Actuator Circuit High
- P0921Gear Shift Forward Actuator Circuit Range/Performance
- P0919Gear Shift Position Control Error
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.