On filed returns in pending status, wait until it's either accepted or rejected before taking action. If rejected, you can update your account and any issues that caused the rejection. Open your return in TurboTax and go through the File section again to update your bank account before re-submitting your return.
n most cases, once the IRS has accepted your return (or you've already mailed it), there's not much you can do. https://ttlc.intuit.com/replies/3302459