What it means
The position sensor or switch of transmission range control channel A reports a circuit/open condition. The TCM cannot verify the actuator position reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The transmission range control A position sensor or switch tells the transmission control module where the A-channel mechanism is positioned. This code sets when the module detects an open circuit, so it cannot reliably confirm the actuator's position.
Common causes
Most likely first.
- Open in sensor signal wire
- Position switch failed open
- 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 data for the commanded range and reported A-channel position to see when the position signal disappears.
- With the vehicle safely parked, compare the gear selected at the shifter with the range displayed by the transmission module.
- Inspect the A position sensor or switch connector for a backed-out pin, corrosion, looseness, or harness damage.
- Check the A sensor signal wire for an open between the sensor and module using the vehicle wiring diagram.
- Test the A position switch or sensor and its connector continuity against the manufacturer's procedure and specification.
Common fixes
- Seat the pushed-back A-channel connector pin and secure the connector.
- Repair an open in the A sensor signal wire.
- Replace the A position switch if it has failed open.
- Clear the code and verify that the module consistently reports A-channel position changes.
Can I keep driving?
Do not drive if the selected range is not reliably recognized, shifts are missing, or the transmission enters limp mode; the vehicle may not respond as expected. If it still selects gears normally, drive only as needed to reach a safe place for diagnosis.
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.