A memory subsystem includes a test engine coupled to a memory controller that can provide memory access transactions to the memory controller, bypassing a memory address decoder. The test engine hardware is configurable for different tests. The test engine identifies a range of addresses through which to iterate a test sequence in response to receiving a software instruction indicating a test to perform. For each iteration of the test, the test engine, via the selected hardware, generates a memory access transaction, selects an address from the range, and sends the transaction to the memory controller. The memory controller schedules memory device commands in response to the transaction, which causes the memory device to execute operations to carry out the transaction.