If the torque sensor is not working on your ABB robot, there could be several potential reasons for this issue. Here are some troubleshooting steps you can try:

1. **Check Connections**: Ensure that all cables and connectors related to the torque sensor are properly connected. Check for any loose connections or damaged cables.

2. **Sensor Calibration**: Perform a calibration procedure for the torque sensor according to the manufacturer's instructions. Calibration ensures accurate readings and corrects any offsets.

3. **Software Configuration**: Verify that the robot controller software is configured correctly to recognize and use the torque sensor. Check the configuration settings and parameters related to the torque sensor in the robot controller interface.

4. **Sensor Health**: Test the torque sensor separately to verify its functionality. If possible, connect the torque sensor to a different system or controller to see if it works properly. This helps determine if the issue lies with the sensor itself or with the robot controller.

5. **Error Messages**: Check the robot controller interface for any error messages or diagnostic information related to the torque sensor. Error codes or diagnostic logs can provide insights into the root cause of the problem.

6. **Firmware Update**: Ensure that the robot controller firmware is up-to-date. Sometimes, firmware updates include bug fixes or improvements related to sensor functionality.

7. **Contact Support**: If you are unable to resolve the issue after performing troubleshooting steps, contact ABB technical support or consult the user manual for further assistance. They can provide specific guidance based on the model of the robot and torque sensor.

By following these steps, you can diagnose and resolve the issue with the torque sensor on your ABB robot.