As the tire tread wears down, the tire becomes more susceptible to puncture and failure. An accepted estimate is that 90% of all tire failures occur during the last 10% of tread life (90% worn). So it is false economy and unsafe to use the tires until they are bald.
If any measurement is less than the service limit, replace the tire (see Tire Removal/Installation in the Wheels/Tires chapter).

Tread Depth Standard:
Front 3.6 mm (0.14 in.)
Rear 5.3 mm (0.21 in.)
Service Limit:
Front 1 mm (0.04 in.) (AT, CH, DE) 1.6 mm (0.06 in.)
Rear 2 mm (0.08 in.) (Up to 130 km/h (80 mph)) 3 mm (0.12 in.) (Over 130 km/h (80 mph))
| WARNING Some replacement tires may adversely affect handling and cause an accident resulting in serious injury or death. To ensure proper handling and stability, use only the recommended standard tires for replacement, inflated to the standard pressure. |
NOTE
Wheel/Tire Damage Inspection
Wheel Bearing Damage InspectionWheel Rotation Sensor Air Gap Inspection
Raise the front/rear wheel off the ground (see Front/Rear
Wheel Removal in the Wheels/Tires chapter).
Measure the air gap between the sensor and sensor rotor
at several points by turning the wheel slowly.
Thickness Gauge [A]
Wheel Rotation Sensor Air Gap
Standard:
Front 0.4 1.6 mm ...
Subthrottle Valve Actuator Input Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Disconnect the subthrottle valve actuator connector and
connect the measuring adapter [A] between these connectors
as shown in the figure.
Main Harness [B]
Subthrottle Valve Actuator [C]
Special Tool ...
DFI Parts Location
Main Throttle Sensor [A]
Subthrottle Sensor [B]
Idle Speed Control Valve Actuator [C]
Subthrottle Valve Actuator [D]
Intake Air Pressure Sensor #2 [E]
Stick Coils #1, #2, #3, #4 [F]
Air Switching Valve [G]
Intake Air Pressure Sensor #1 [H]
Water Temperature Sensor [A]
Primary Fuel Injec ...