The Kenmore inteliCLEAN automatically chooses the right cleaning power for any cleaning need.
When inteliCLEAN mode is activated the inteliCLEAN indicator is green.
To turn OFF or de-activate inteliCLEAN press the inteliCLEAN button or TOOLS button.
With heavy dirt concentration the dirt sensor is amber and red, indicating that inteliCLEAN power is at MAXIMUM, The vacuum cleaner operates at its highest energy consumption and noise levels.
You can find parts and diagrams on Sears PartsDirect: searspartsdirect.com/model/17ajc8st3s-000582/kenmore-11635923500-upright-vacuum-parts
You can find more on page 9 of your owners manual. The dirt sensor is #18 in the schematic diagram on Sears PartsDirect at the link above.