The ASCD steering switch is a crucial component in Nissan vehicles that controls the Automatic Speed Control Device (ASCD), commonly known as cruise control. Understanding its functionality, common issues, and troubleshooting methods is essential for vehicle owners experiencing problems with their cruise control system.

Understanding the ASCD Steering Switch

The ASCD steering switch is integrated into the steering wheel and allows drivers to activate and manage the cruise control system. It sends varying electrical resistance signals to the Engine Control Module (ECM), which interprets these signals to determine which function (such as setting or canceling cruise control) is being requested. If the switch malfunctions, it can trigger error codes like P1564, indicating a problem with the cruise control system.

Common Issues with the ASCD Steering Switch

  • Malfunctioning Switch: The ASCD switch may fail due to wear or internal damage, causing it to send incorrect signals to the ECM.

  • Wiring Problems: Damaged or corroded wiring can disrupt communication between the ASCD switch and the ECM, leading to operational failures.

  • ECM Faults: Although less common, a malfunctioning ECM can also be a source of issues related to the ASCD system.

Troubleshooting Steps

1. Check for Error Codes: Use an OBD-II scanner to check for any stored error codes. The presence of code P1564 indicates a potential issue with the ASCD steering switch.

2. Inspect Wiring and Connections: Examine the wiring harness connected to the ASCD steering switch for any signs of damage or corrosion. Ensure all connections are secure.

3. Test Voltage Output: Measure the voltage output from the ASCD steering switch using a multimeter. Each button on the switch should produce a specific voltage when pressed:

- OFF position: Approximately 4V

- SET/COAST button pressed: Approximately 2V

- RESUME/ACCEL button pressed: Approximately 3V

- CANCEL button pressed: Approximately 1V

4. Replace the ASCD Steering Switch: If testing confirms that the switch is faulty, replace it with a new unit. Ensure that you disconnect the battery before starting this process to avoid airbag deployment.

5. Recheck System Functionality: After replacing the switch, clear any error codes and test the cruise control system to ensure it operates correctly.

Important Considerations

  • If replacing the ASCD steering switch does not resolve the issue, further investigation into wiring or ECM problems may be necessary.

  • Always refer to your vehicle’s service manual for specific diagnostic procedures and specifications related to your model.

FAQs About ASCD Steering Switch

    • What does P1564 mean?
      P1564 indicates an issue with the ASCD steering switch, often linked to malfunctioning cruise control.
    • Can I replace the ASCD steering switch myself?
      Yes, if you have basic mechanical skills, you can replace it by following proper safety precautions.
    • How do I know if my wiring is faulty?
      Test for continuity and inspect for visible damage or corrosion in the wiring harness connected to the ASCD switch.