Circuit/System Testing

Ignition ON.
Verify that no G13 generator or B18 battery current sensor DTCs are set that would cause a charging system concern.
- If DTCs are set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If no DTCs are set
Ignition OFF, measure the voltage across the battery terminals.
Verify battery voltage is 12.0 V or greater at room temperature.
- If less than 12.0 V
  Refer to Battery Inspection/Test .
Engine ON, all electrical accessories OFF, increase engine speed to 2,500 RPM.
Verify the battery voltage is between 12.6-15.0 V.
- If less than 12.6 V or greater than 15.0 V
  Replace the K59 starter/generator control module.
- If between 12.6-15.0 V
Engine ON, all electrical accessories ON, increase engine speed to 2,500 RPM.
Verify the battery voltage is between 12.6-15.0 V.
- If less than 12.6 V or greater than 15.0 V
  Replace the K59 starter/generator control module.
- If between 12.6-15.0 V
All OK.