What it means
The transmission control module monitors the electrical circuit for the gear shift reverse actuator. It sets this code when it detects an open circuit in that actuator circuit.
At a glance
- Usually lights the check-engine light
How it works
The transmission control module monitors the electrical path to the reverse shift actuator, which moves the mechanism into reverse. This code sets when that path is detected as open, preventing a dependable reverse actuator command.
Common causes
Most likely first.
- Actuator open winding
- Wiring break
- Pin pushed back out of connector body
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and check live gear and actuator status when reverse is selected to see whether the open fault appears with that command.
- Inspect the reverse actuator connector for loose or pushed-back pins, corrosion, and wire damage.
- Trace the reverse actuator wiring for a break or chafe, and gently move the harness while monitoring for an intermittent open.
- Test continuity through the reverse actuator circuit and actuator winding using the wiring diagram and manufacturer's procedure.
- If those tests pass, check the transmission control module's reverse output using the manufacturer's specification.
Common fixes
- Reseat a loose or pushed-back connector pin at the reverse actuator.
- Repair an open or damaged section of reverse actuator wiring.
- Replace the reverse actuator if its winding tests open.
- Repair the module output only if testing isolates the fault to the control module.
Can I keep driving?
Reverse may be unavailable, which can make parking or maneuvering unsafe; avoid driving if you cannot move and park the vehicle safely. If forward gears are also affected, stop and arrange recovery.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.