Electrolux Dishwasher Error Code i91

The i91 code means the dishwasher has detected an MCF checksum error, which is a communication failure between the main control board and the display board. When the main board sends an identification request at startup and the display board's response does not match, the machine logs i91 and prevents any program from starting. This is a protective measure to stop the appliance from running under unverified control conditions.

A power cycle reset will clear the i91 error if it was caused by a temporary communication glitch at startup. Simply disconnect power for 60 seconds, then restore it. However, if the underlying issue is a faulty connector, damaged harness, or failed board, the error will return on the next startup cycle and a reset alone will not resolve it.

If a simple connector reseating or power reset resolves the issue, there is no parts cost. If the display board needs replacement, parts and labor typically range from $150 to $350 depending on the specific model and local labor rates. A main control board replacement is generally more expensive, often falling in the $200 to $450 range for parts and labor combined.

In many cases, yes. Start by unplugging the dishwasher for at least 60 seconds and plugging it back in. If the code clears, a transient glitch was the cause. If i91 returns, you can inspect the wiring harness and connectors between the display board and main board for loose or corroded pins and reseat them. Beyond that, replacing a board typically requires a technician unless you are comfortable working with appliance electronics.

The i91 error blocks program start entirely, so the dishwasher will not run while the fault is active. There is no immediate safety hazard from the error itself, but you should not attempt to bypass the lockout. Address the underlying communication fault before returning the unit to normal use.