E4 appears shortly after starting a pressure program; cooker may not build pressure.

Safety first: Unplug the cooker and ensure all pressure is released before disassembling any valve components. Never attempt to open the lid under pressure.

• Release pressure: Move the steam release handle to the venting position (if present) and wait until all steam escapes and the float valve drops.
• Clean steam release valve: Remove the steam release cap from the lid (on ETA models with removable caps). Rinse under warm water and clear any food particles with a soft brush.
• Inspect anti-block shield: On the underside of the lid, remove the metal anti-block shield (small cover over the steam outlet). Clean thoroughly to remove starch or foam buildup.
• Check safety valve: Ensure the safety valve pin moves freely up and down. Clean around it and verify the silicone gasket is intact.
• Reassemble and test: Refit all lid components securely, add water to the pot, and run a short pressure program to test.

When to call a technician: If E4 persists with clean valves and normal filling, the pressure sensor or control board may be faulty. Do not bypass safety devices; seek professional service.