E17 error appears and the cooker refuses to start any pressure program, though non-pressure modes may work.

Safety first: Ensure the cooker is unplugged and fully depressurized before working on the lid.

• Locate pressure pin: On many Lagostina models, a small metal or plastic pin near the lid handle pops up when under pressure. Check that it moves freely.
• Clean around pin: Use a damp cloth and a soft brush to remove dried food or starch around the pin and its guide.
• Lubricate lightly: Apply a tiny amount of food-safe silicone lubricant to the pin shaft if it feels sticky (avoid getting lubricant into the food chamber).
• Check interlock switch: With the lid open (unplugged), gently press the pin from inside and listen for a click from the interlock microswitch. If no click, the switch or its actuator may be broken.

If cleaning and freeing the pin does not clear E17, the lid interlock assembly should be replaced.