Backup Power Supply Inspection: Notes

Disconnect the negative battery terminal.
Remove the backup power supply. (See BACKUP POWER SUPPLY REMOVAL/INSTALLATION [(US)] )
Connect the backup power supply connector.
Connect the negative battery terminal.
Verify that the voltages of each of the terminals are as indicated in the terminal voltage table (reference).

If the voltage is not as specified in the terminal voltage table (reference), inspect the parts under Inspection item(s) and related wiring harnesses.

If the system does not operate normally even though the inspection items are normal, replace the backup power supply. (See BACKUP POWER SUPPLY REMOVAL/INSTALLATION [(US)] .)