P0904 and related codes: gate select and gear shift actuators
In an automated manual gearbox, the actuator that picks the gate, the one that pushes the gear in, their position sensors, the gear shift lock, the manual mode controls or the shift adaptation has a fault.
SeverityHighCarrying on can cause expensive damage, so deal with it now.
Can you keep driving?Only as far as the workshopWhat does P0904 mean?
Changing gear in a manual gearbox takes two movements: across, to choose the gate, and along, to push the gear in. An automated manual gearbox makes both with electric or hydraulic actuators, and position sensors confirm each movement. These codes say that one of those movements or its sensor failed, that an actuator overheated, or that the manual mode switch, the gear shift lock or the learned positions are out of order. When the computer cannot confirm the gear, it usually stops changing and holds the gear it has, or neutral.
What causes P0904?
- A worn or seized gear selection actuator
- A position sensor out of adjustment or with a damaged connector
- Low hydraulic pressure from the unit that feeds the actuators
- A worn selector mechanism inside the gearbox that the actuator cannot move cleanly
- Learned positions lost after a battery disconnection or a repair
What to check first for P0904
- Note whether the fault appears when selecting a particular gear or reverse
- Have the actuator positions read live on a scan tool while gears are selected
- Inspect the actuator connectors for corrosion, since they sit low on the gearbox
- Have the gear positions relearned with the right tool after a repair or a battery disconnection
Can you drive with P0904?
Drive only to a workshop, and only if the car still changes gear. If it is stuck in neutral or in one gear, or will not select reverse, do not force it; have it towed, especially if you cannot pull away from a stop safely.
In states with an OBD-II emissions inspection, a car with the check engine light on fails the test until the fault is fixed.
Codes on this page
46
- P0904Gate Select Position Circuit
- P0905Gate Select Position Circuit Range/Performance
- P0906Gate Select Position Circuit Low
- P0907Gate Select Position Circuit High
- P0908Gate Select Position Circuit Intermittent
- P0909Gate Select Control Error
- P0910Gate Select Actuator Circuit/Open
- P0911Gate Select Actuator Circuit Range/Performance
- P0912Gate Select Actuator Circuit Low
- P0913Gate Select Actuator Circuit High
- P0914Gear Shift Position Circuit
- P0915Gear Shift Position Circuit Range/Performance
- P0916Gear Shift Position Circuit Low
- P0917Gear Shift Position Circuit High
- P0918Gear Shift Position Circuit Intermittent
- P0919Gear Shift Position Control Error
- P0920Gear Shift Forward Actuator Circuit/Open
- P0921Gear Shift Forward Actuator Circuit Range/Performance
- P0922Gear Shift Forward Actuator Circuit Low
- P0923Gear Shift Forward Actuator Circuit High
- P0924Gear Shift Reverse Actuator Circuit/Open
- P0925Gear Shift Reverse Actuator Circuit Range/Performance
- P0926Gear Shift Reverse Actuator Circuit Low
- P0927Gear Shift Reverse Actuator Circuit High
- P0928Gear Shift Lock Solenoid Control Circuit/Open
- P0929Gear Shift Lock Solenoid Control Circuit Range/Performance
- P0930Gear Shift Lock Solenoid Control Circuit Low
- P0931Gear Shift Lock Solenoid Control Circuit High
- P0950Auto Shift Manual Control Circuit
- P0951Auto Shift Manual Control Circuit Range/Performance
- P0952Auto Shift Manual Control Circuit Low
- P0953Auto Shift Manual Control Circuit High
- P0954Auto Shift Manual Control Circuit Intermittent
- P0955Auto Shift Manual Mode Circuit
- P0956Auto Shift Manual Mode Circuit Range/Performance
- P0957Auto Shift Manual Mode Circuit Low
- P0958Auto Shift Manual Mode Circuit High
- P0959Auto Shift Manual Mode Circuit Intermittent
- P2786Gear Shift Actuator Temperature Too High
- P2788Auto Shift Manual Adaptive Learning at Limit
- P2790Gate Select Direction Circuit
- P2791Gate Select Direction Circuit Low
- P2792Gate Select Direction Circuit High
- P2793Gear Shift Direction Circuit
- P2794Gear Shift Direction Circuit Low
- P2795Gear Shift Direction Circuit High
Related codes
Checked on · Rafael Soares
These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.
