Hino Motors HINO 155 series Workshop Manual page 281

7. After-inspection work
• Clear all past DTCs.
• Check that no DTC is stored after test drive.
8. Estimated failure factors
Engine coolant temperature sensor:
• Loose/disconnected sensor or failure in sensing area (contamination, clogging or breakage)
• Abnormal resistance of the engine coolant temperature sensor
• Engine ECU sensor power supply failure or internal circuit failure
• Disconnection or short-circuit in sensor harness
• Irregular contact
ENGINE (J05E)/TROUBLESHOOTING 2–245