Based on your maintenance schedule, the Honda Maintenance Minder System provides subcodes that indicate further services your car requires. The first subcode describes tire rotation. Subcode 2 denotes replacing the air cleaner element, checking the drive belt, and changing the dust and pollen filter. The changing of both the transfer fluids and the gearbox is implied by Subcode 3. Subcode 4 performs a valve clearance check, replaces the spark plugs, fixes the timing belt (if present), and examines the valves. The engine coolant has to be replaced, according to Sub Code 5. Subcode 6 refers to replacing the fluid in the rear differential (if necessary), whereas Subcode 7 refers to replacing the fluid in the brakes.