LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Buick >> 1991 >> Reatta 2D Convertible >> Repair and Diagnosis >> Electrical >> Charging Systems >> Alternator & Regulator >> Trouble Code Charts >> Trouble Code B410 - Charging System Circuit >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

  1. BCM input BI51 displays alternator signal voltage as HI or LO depending on the voltage state at the BCM. Normally with key on and engine off, circuit No. 25 will be pulled LO by the alternator (BI51 reads LO).
  2. This step checks if the LO reading is due to circuit No. 25 or the alternator. If the reading changes from LO to HI when the alternator is disconnected, circuit No. 25 and the BCM are okay.
  3. This step determines if the fault is due to the BCM or circuit No. 25.
  4. BCM data value BD51 displays the amount of alternator field activity. Under normal conditions, a reading less than 7 percent would indicate a fault in the field circuit or the BCM.
  5. Removing the alternator connector will determine if the fault is due to the alternator or an open in circuit No. 25, including the BCM and interface connector.
scientia non olet · About LEMON Manuals