Yes, Walmart will use Telecheck to process and verify checks and make sure they clear your checking account.
When you present your check to the sales clerk, your check is authorized through a specially-designed, secure TeleCheck system that captures banking information and the amount of the check. Once the check is approved, you'll receive a receipt of the electronic transaction to sign. When you sign the receipt, you will receive a copy for your records along with your check to keep. It's that simple.
Telecheck is an electronic way of processing your checks, they send it through the computer and based on your banks routing number and your own account number it contacts the banks mainframe to verify that you have the amount in your account to cover the check you just wrote. it then puts a hold on the funds and you get your check back voided out. Walmart and a lot of companies are starting to do this now because of having problems with too many people writing bad checks that bounce like a rubber ball and then not being able to get in contact with them to collect funds that the store(s) were shorted.