With Automatic Transmission

Set speed does not resume when the resume/accel button is pressed (with the cruise control main switch turned on, and set speed temporarily canceled by pressing the brake pedal)

Set speed does not resume when the resume/accel button is pressed (with the cruise control main switch turned on, and set speed temporarily canceled by pressing the brake pedal)

Check for PGM-FI DTCs Initial Inspection and Diagnostic Overview.

Do the cruise control combination switch test Testing and Inspection.

Do the cruise control input test Component Tests and General Diagnostics.
Test the resume/accel switch signal input.

Also check for

Open circuit, loose or disconnected terminals: LT BLU or GRY wire