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 InspectionStick Coil Input Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the ECU (see ECU Removal in the Fuel System
(DFI) chapter).
Do not disconnect the ECU connectors.
Connect a digital meter [A] to the connector [B] with the
needle adapter set.
Special Tool - N ...
Antenna Resistance Inspection
Turn the ignition switch to OFF.
Remove the air cleaner housing (see Air Cleaner Housing
Removal in the Fuel System (DFI) chapter).
Disconnect the antenna lead connector [A].
Measure the antenna resistance.
Antenna Resistance
Connections: BK lead ←→ BK/W lead
Standard: Ab ...
Wheel 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 ...