WOMS
B code body Medium severity

B1838 Battery Saver Power Relay Circuit Failure

The OBD2 code B1838 indicates a failure in the battery saver power relay circuit, which may affect the operation of electrical components that rely on this relay for power management

Definition

The OBD2 code B1838 indicates a failure in the battery saver power relay circuit, which may affect the operation of electrical components that rely on this relay for power management

Common causes

  • Faulty battery saver relay
  • Damaged wiring or connectors
  • Short circuit in the circuit
  • Open circuit in the circuit
  • Faulty body control module (BCM)
  • Corroded terminals
  • Poor ground connection
  • Malfunctioning ignition switch

Common misdiagnoses

  • Faulty battery
  • Bad alternator
  • Corroded battery terminals
  • Wiring issues
  • Faulty power relay
  • Malfunctioning body control module (BCM)
  • Incorrectly installed aftermarket accessories
  • Software issues in the vehicle's computer system

Troubleshooting steps

  1. 1. Check the Battery and Charging System

    Inspect the Battery: Ensure the battery is in good condition, fully charged, and free of corrosion on terminals

  2. 2. Test the Alternator

    Verify that the alternator is charging the battery properly. A failing alternator can lead to low voltage issues

  3. 3. Inspect the Battery Saver Relay

    Locate the Relay: Find the battery saver relay in the vehicle’s fuse box or relay panel

  4. 4. Visual Inspection

    Check for any signs of damage, corrosion, or burnt contacts

  5. 5. Test the Relay

    Use a multimeter to test the relay for continuity and proper operation. You can also swap it with a similar relay (if available) to see if the issue persists

  6. 6. Check Wiring and Connectors

    Inspect Wiring: Look for damaged, frayed, or shorted wires in the battery saver relay circuit

  7. 7. Check Connectors

    Ensure all connectors are secure and free of corrosion. Clean any corroded connections

  8. 8. Examine the Power Distribution

    Check Fuses: Inspect any related fuses for continuity. Replace any blown fuses

  9. 9. Test Voltage

    Use a multimeter to check for proper voltage at the relay and other components in the circuit

  10. 10. Scan for Additional Codes

    Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes that may provide more context to the issue

  11. 11. Clear Codes

    After performing repairs, clear the codes and see if B1838 returns

  12. 12. Inspect Related Components

    Check for Ground Issues: Ensure that all ground connections related to the battery saver circuit are secure and free of corrosion

  13. 13. Look for Other Malfunctions

    Sometimes, other components controlled by the battery saver relay may be malfunctioning, leading to this code

  14. 14. Consult Wiring Diagrams

    Refer to Service Manual: Use the vehicle’s service manual to understand the wiring diagram for the battery saver relay circuit. This can help identify any specific components that may be causing the issue

  15. 15. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or technician who can perform more advanced diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1838 code. Always ensure safety precautions are taken when working on electrical systems in vehicles