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 InspectionCrankshaft Sensor Peak Voltage Inspection
NOTE
Be sure the battery is fully charged.
Using the peak voltage adapter [A] is more reliable way
to determine the condition of the crankshaft sensor than
crankshaft sensor internal resistance measurements.
Disconnect the crankshaft sensor lead connector (see
Crankshaft Sensor ...
Check 3-5: Warning Indicator Light (Red LED) (Oil Pressure Warning)
Inspection
Connect the leads in the same circuit as Check 3-2.
Connect the terminal [10] to the battery (–) terminal.
Check that the oil pressure warning symbol [A] and the
warning indicator light (Red LED) [B] go on.
If the indicator light does not go on, replace the meter unit.
...
Warning Indicator Light (LED)
Light (LED) Inspection
The warning indicator light (LED) [A] is used for the FI indicator,
immobilizer indicator (immobilizer equipped models),
water temperature warning indicator and oil pressure
warning indicator.
In this model, the warning indicator light (LED) (FI/immobilizer)
goes ...