check engine light came on, mileage on odometer disappeared? on 1998 Lexus ES300

What could be the problem? The mileage shown on the odometer disappeared first then a few minutes later the check engine light came on. Mileage reappeared minutes later and has now disappeared again.
Would greatly appreciate your help.
Thank you......

Asked by for the 1998 Lexus ES300
have codes scanned and post so we can adv