What it means
The gate select position circuit A reports a circuit a low fault. Selector gate position cannot be reliably measured.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Gate Select Position Circuit A reports the selected shift gate to the transmission controller on an automated manual transmission. This code sets when Circuit A's signal falls below the permitted range, so the controller cannot reliably determine the selector gate.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
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
- Record freeze-frame data and monitor Circuit A gate position data with a scan tool while moving the selector to see whether the signal remains low.
- Inspect the Circuit A sensor connector and harness for damaged insulation, a signal wire shorted to ground, or a shorted sensor.
- Check sensor supply, ground, and Circuit A signal voltage and continuity against the wiring diagram and manufacturer's specification.
- If the harness is intact, test the gate select position sensor output through the selector's range using the manufacturer's procedure.
- If the sensor signal is correct but the indicated gate is wrong, inspect selector linkage and the gate mechanism for looseness or misalignment.
Common fixes
- Repair a Circuit A signal wire shorted to ground.
- Clean and secure the gate select sensor connector.
- Replace a gate select position sensor that tests shorted or fails to produce a valid signal.
- Correct selector linkage looseness or misalignment if it prevents reliable gate selection.
Can I keep driving?
Do not continue driving if gear selection becomes unreliable, shifts are missing, or limp mode engages; the controller may be unable to confirm the selected gate. Stop safely and arrange prompt diagnosis if the transmission cannot select gears consistently.
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.