P1245 Alternator Load Input Failed Low

Possible causes
  • GEN-COM circuit short to GND.
  • GEN-MON circuit short to GND.
  • Open B+ wire during operation.
  • Low system voltage.
  • Broken generator belt.
  • Damaged generator/regulator assembly.
  • Damaged PCM.
    • Tech notes
  • Verify the battery voltage is 14.5 volts.
  • Verify the generator/regulator has the correct part number.

    • Symptoms
    – Engine Light ON (or Service Engine Soon Warning Light)
    P1245 Description
    The PCM monitors generator load from the generator/regulator in the form of frequency. The fault indicates the input is lower than the load should be in normal operation. The load input could be low when no generator output exists.
    P1245 Information for specific makes
    P1245 BUICK
    P1245 CADILLAC
    P1245 CHEVROLET
    P1245 FORD
    P1245 GMC
    P1245 SUBARU