What it means
The drive circuit of throttle actuator motor B is open. Throttle B is the secondary throttle on engines with two throttle bodies — typically used for tumble flap or charge-motion control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Throttle actuator B is the motor circuit for a secondary throttle body, used on some engines to control airflow features such as charge motion. The control module monitors the B motor’s drive circuit and sets P210A when it detects an open path, so the motor cannot receive the commanded drive current.
Common causes
Most likely first.
- Motor winding open
- Open wire to motor
- Pin pushed back out of connector body
Symptoms
- Check engine light on
- Reduced throttle response, possible limp mode
- Hesitation or surging
- Idle too high or too low
How to diagnose it
- Use a scan tool to record freeze-frame data and check for related throttle codes, which can show whether the B circuit fault appeared during a particular operating condition.
- With the ignition off, inspect the secondary throttle body B connector for a pushed-back pin, corrosion, moisture, or a loose fit.
- Follow the B motor wiring and look for breaks, chafing, or damage, paying attention to areas where the harness bends or contacts other parts.
- Check continuity through the B motor circuit and its wiring using the vehicle wiring diagram to locate an open connection.
- If the wiring and connector pass inspection, test the throttle actuator B motor winding against the manufacturer's specification.
Common fixes
- Reconnect the B motor connector or repair a pushed-back terminal.
- Repair an open or damaged wire in the throttle actuator B circuit.
- Replace a throttle actuator B motor with an open winding.
- Replace the affected connector or terminals if they cannot maintain a sound connection.
Can I keep driving?
Drive only if throttle response remains predictable and the vehicle can be controlled safely; avoid high speeds and situations that require quick acceleration. Reduced power or an unstable idle can make merging and manoeuvring unsafe, so stop driving if the throttle response becomes erratic.
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.