Description:

This error code indicates that the switched supply voltage to the Selective Control Valve Unit IV (SV IV) has exceeded 16.0 volts. Such an overvoltage condition may be caused by issues such as a faulty voltage regulator, wiring problems, or an issue within the Vehicle Load Center (VLC).

Reaction:

Upon detecting this overvoltage condition, the equipment may exhibit erratic behavior in the SV IV, such as improper valve operation. A diagnostic warning will appear on the control panel.

Recommendations:

• Inspect Voltage Regulator:
  • Ensure the voltage regulator is functioning correctly and not allowing voltage spikes. Replace if defective.
• Check Wiring:
  • Examine the wiring associated with the SV IV for any signs of damage, loose connections, or corrosion. Repair or replace any compromised wiring.
• Perform VLC Diagnostics:
  • Since the VLC control unit wake-up circuit is the voltage source, begin diagnostics with the VLC. Check for related codes and address any issues found.
  • Follow the VLC diagnostic procedures to ensure it is operating within normal voltage ranges.
• Inspect Power Supply:
  • Verify that the power supply to the SV IV is stable and within the specified voltage range.

Note:

• Associated Codes:
  • This code and other 000158.XX codes may be present in other control units. It is important to address all associated codes systematically, starting with the VLC control unit diagnostics.
• Preventive Measures:
  • Regularly monitor and maintain the electrical systems to prevent voltage-related issues. Ensure all connections and components are in good condition to avoid overvoltage situations.

By following these steps, you can address the SV4 000158.03 error code effectively and ensure the proper operation of the Selective Control Valve Unit IV.