Three digit codes(YMM): Last digit of year then month of the year. I don't think the 80s had a code so its only for the 90's. In 2000 they changed to the four digit codes.
Four Digit Codes(YYWW): Last two digits of the year followed by the week of the year. The date codes may not always be exact. Serial Number is the most accurate. Besides if the unit is stolen or tampered with its warranty may have been voided and it would say it on the serial number card. Call the 800# or email them.
Four Digit Codes(YYWW): Last two digits of the year followed by the week of the year. The date codes may not always be exact. Serial Number is the most accurate. Besides if the unit is stolen or tampered with its warranty may have been voided and it would say it on the serial number card. Call the 800# or email them.