If the reading is within the standard, but the problem still exists, replace the ECU (see ECU Removal/Installation in the Fuel System (DFI) chapter).
Water Temperature Sensor Circuit

1. ECU
2. Water Temperature Sensor
Water Temperature Sensor Output Voltage InspectionCrankshaft Sensor Inspection
Disconnect the crankshaft sensor lead connector (see
Crankshaft Sensor Removal).
Set the hand tester [A] to the × 10 Ω range and connect it
to the crankshaft sensor lead connector [B].
Special Tool - Hand Tester: 57001-1394
Crankshaft Sensor Resistance
Connections:
Meter (+ ...
Fuse Inspection
Remove the fuse.
Inspect the fuse element.
If it is blown out, replace the fuse. Before replacing a
blown fuse, always check the amperage in the affected
circuit. If the amperage is equal to or greater than the
fuse rating, check the wiring and related components for
a short circuit.
...
Oil Pressure Switch Installation
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant to the threads of the oil pressure
switch, and tighten it.
Sealant - Liquid Gasket, TB1211: 56019-120
Torque - Oil Pressure ...