You can buy a bond that forces Tesla to repay you $1 in X years, for 89 cents.
Bonds trading below value happen when there is uncertainty whether it can actually be repaid in the future by the company (e.g. maybe it is unsecured debt).
If repaid the yield would have been 5.3% per annum + the 11% difference it trades below value
Yes Tesla's latest unsecured bonds have a coupon rate of 5.3% which they pay biannually. So for a bond with a face value of $1 they will pay you ~2.6 cents every 6 months.
Bonds trading below value happen when there is uncertainty whether it can actually be repaid in the future by the company (e.g. maybe it is unsecured debt).
If repaid the yield would have been 5.3% per annum + the 11% difference it trades below value