Hino U02A2 Fault Code: Communication disrupt (DEF tank sensor)

TECHNICAL DESCRIPTION

DEF tank sensor communicates with DCU via CAN

DESCRIPTION OF MALFUNCTION

CAN communication with DEF sensor is interrupted

DTC SET CONDITION

Check Condition:

• Starter switch ON
• DCU power supply voltage is 11 V – 16 V

Judgment Criteria:

CAN data from DEF sensor are not received for at least 30 seconds

RESET CONDITION

After normal operation is restored and the starter switch is turned OFF

INDICATION, WARNING OR SYSTEM CONTROL REGULATION WHEN THE DTC IS SET

• MIL: ON
• SCR malfunction light: ON
• If malfunction does not improve within 500 miles: engine output is restricted
• If malfunction does not improve within 2,000 miles: vehicle speed is restricted

SYMPTOMS ON THE VEHICLE WHEN THE DTC IS SET

Symptoms on the Vehicle Due to Backup Control (Fail Safe Function):

• Engine output is insufficient (when malfunction does not improve within 500 miles)
• Vehicle does not speed up (when malfunction does not improve within 2,000 miles)

PRE-INSPECTION WORK

Check that the battery voltage is in the normal range

AFTER-INSPECTION WORK 

• Clear all past DTCs
• Check if the DTC is stored after test drive

POSSIBLE CAUSES 

• CAN circuit failure (engine CAN)
• DEF sensor failure
• DEF sensor power supply/GND harness disconnection or short-circuit

INSPECTION PROCEDURE

TROUBLESHOOTING STEPS

Refer to the Engine CAN Communication line in the CAN communication diagnostic information

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