Gas cooktop display shows E4 and one burner will not ignite, others work normally

Safety first: Turn off gas and power. Allow the cooktop to cool before removing burner parts.

User actions:

• Remove the affected burner cap and crown. Clean all burner ports, especially near the ignition electrode, with a soft brush or wooden toothpick.
• Ensure the burner parts are dry and correctly seated when reassembled.
• Try lighting again.

Technician actions:

• Inspect the ignition electrode for cracks or heavy deposits; replace if damaged.
• Check continuity of the ignition wire from the spark module to the electrode.
• Swap ignition leads at the spark module (if possible) to see if the fault follows the lead or stays with the burner output; this helps identify a bad module output.
• Replace the spark module if one output is dead and wiring/electrode are good.