Hino Motors HINO 155 series Workshop Manual page 245

6. Pre-inspection work
• Check that the battery voltage is in the normal range.
7. After-inspection work
• Clear all past DTCs.
• Check that no DTC is stored after test drive.
8. Estimated failure factors
• Sensor disconnected from the measured part or sensing unit malfunctioning (due to dirt, clogging, damage, etc.
• Engine ECU sensor power supply (air flow sensor dedicated 12 V power supply) malfunction or internal circuit mal-
function
• Sensor harness disconnection, short-circuit
• Poor connector contact or faulty connector fit
• Sensor harness high frequency noise
ENGINE (J05E)/TROUBLESHOOTING 2–209