Subject to the other provisions of Article 5 (commencing with Section 1805.1), the finance charge to be included in a consolidated total of payments under subdivision (l) of Section 1808.2 shall be determined by applying the finance charge at the applicable rate to the unpaid balance under subdivision (j) of Section 1808.2, for the period from the date of the consolidation to and including the date when the final installment of the consolidated total is payable.
Ca. Civ. Code § 1808.5