California Code, Civil Code - CIV § 1917.140

The borrower may, at any time for the purpose of facilitating a sale of the property, request the lender to stipulate the minimum amount which the lender considers to be the fair market value of the property for the purposes of this chapter.  The lender shall advise the borrower within 10 working days of the receipt of such request of the lender's estimate of the minimum fair market value.  The estimate shall remain effective for purposes of this section for 90 days.  For the purposes of this section and Section 1917.141, a sale of the property shall be deemed to have occurred within the 90-day period if there is a valid contract entered by an offer and acceptance within the 90-day period for the sale of the property.  The lender's stipulation shall remain effective for an additional 60 days following execution of the sale contract to permit completion of the sale and close of escrow.

The lender shall not be liable to the borrower or any other party on account of damages alleged as a result of providing the stipulation or estimate required by this section if such stipulation or estimate is made in good faith.  Evidence of lack of good faith shall include, but not be limited to, a showing that the lender has willfully or repeatedly overrepresented the fair market value of other properties in similar situations, applying equitable principles to those determinations.  The lender shall be conclusively presumed to have acted in good faith and no action may be brought or maintained against a lender which arises out of the provision by the lender of such stipulation or estimate, if the lender relied upon an appraisal of an independent appraiser approved by the Federal National Mortgage Association.