WOMS
P code powertrain Medium severity

P1244 Alternator Load Input Failed High

The OBD2 code P1244 indicates that the engine control module (ECM) has detected a high voltage signal from the alternator load input, suggesting a potential issue with the alternator or its related circuitry

Definition

The OBD2 code P1244 indicates that the engine control module (ECM) has detected a high voltage signal from the alternator load input, suggesting a potential issue with the alternator or its related circuitry

Common causes

  • Faulty alternator
  • Bad alternator connections or wiring
  • Failed voltage regulator
  • Damaged or corroded connectors
  • Faulty battery
  • Issues with the engine control module (ECM)
  • Short circuit in the alternator load input circuit
  • Open circuit in the alternator load input circuit

Common misdiagnoses

  • Faulty alternator
  • Bad battery
  • Defective voltage regulator
  • Wiring issues or shorts
  • Faulty engine control module (ECM)
  • Poor ground connections
  • Incorrectly installed aftermarket accessories
  • Sensor malfunctions (e.g., throttle position sensor)

Troubleshooting steps

  1. 1. Check the Battery:

    Voltage Test: Use a multimeter to check the battery voltage. It should be around 12.6 volts when the engine is off and between 13.7 to 14.7 volts when the engine is running

  2. 2. Load Test

    Perform a load test on the battery to ensure it can hold a charge

  3. 3. Inspect the Alternator:

    Visual Inspection: Check for any physical damage, loose connections, or corrosion on the alternator terminals

  4. 4. Belt Condition

    Ensure the serpentine belt is in good condition and properly tensioned

  5. 5. Check Wiring and Connectors:

    Inspect Wiring: Look for damaged, frayed, or corroded wires leading to the alternator and ECM

  6. 6. Connector Check

    Ensure that all connectors are secure and free of corrosion

  7. 7. Test the Alternator Output:

    Voltage Output: With the engine running, measure the voltage output of the alternator. It should be within the specified range (typically 13.7 to 14.7 volts)

  8. 8. Load Test

    If possible, perform a load test on the alternator to ensure it can handle the electrical load

  9. 9. Check the ECM:

    Software Updates: Ensure that the ECM has the latest software updates from the manufacturer

  10. 10. Diagnostic Scan

    Use a scan tool to check for any other related trouble codes that may provide additional context

  11. 11. Inspect the Alternator Load Input Signal:

    Signal Testing: Use a multimeter or oscilloscope to check the alternator load input signal to the ECM. Ensure it is within the expected range

  12. 12. Ground Check

    Verify that the ground connection for the alternator is solid and free of corrosion

  13. 13. Clear Codes and Test Drive:

    After performing the above checks and repairs, clear the trouble codes using a scan tool

  14. 14. Take the vehicle for a test drive to see if the code reappears

  15. 15. Professional Diagnosis:

    If you are unable to resolve the issue, consider seeking help from a professional mechanic who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the P1244 code