Hino U0100 Fault Code: Denox ECU can communication (ECM)

TECHNICAL DESCRIPTION

The DCU carries out CAN communication with the engine ECU via CAN circuit A (ENGINE CAN LINE/250 k) and CAN circuit B (DIAGNOSIS CAN LINE/500 k)..

DESCRIPTION OF MALFUNCTION

CAN communication signal reception error is detected

DTC SET CONDITION

DTC Detection Condition:

Starter switch ON.

Judgment Criteria:

CAN communication signal from the engine ECU cannot be received.

RESET CONDITION

After having restored to the normal conditions.

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

− DEF injection is restricted.

− NOx reduction quantity monitoring is aborted

SYMPTOMS ON THE VEHICLE WHEN THE DTC IS SET

Symptoms on the Vehicle Due to Malfunction:

Exhaust gas purification function decline.

PRE-INSPECTION WORK

Check that the battery voltage is in the normal range.

AFTER-INSPECTION WORK

− Clear all past DTCs.

− Check if no DTC is stored after test drive.

POSSIBLE CAUSES

− Looseness or poor contact of the connector

− DCU malfunction

− Engine ECU malfunction.

INSPECTION PROCEDURE

TROUBLESHOOTING STEPS

Step 1) Check the DTC detected (Engine).

1. Connect the vehicle to the diagnostic tool.
2. Set the starter switch to the “ON” position.
3. Select [Engine] and check if the following CAN communication system DTCs have been detected.

CAN A LINE (ENGINE CAN LINE/250k): U010A, U010C, U029D, U029E, U0073, U010E, U02A2

CAN B LINE (DIAGNOSIS CAN LINE/500k): U1001, U110A

Were the multiple CAN communication system DTCs detected?

Step 2) Inspect the connector.

Check the connection of the joint connector No.30_J/C, Common rail_CAN_J/C3 and DCU connector (Looseness and poor contact).

Were any failures found?

Step 3) Check the DTC detected (DCU).

1. Set the starter switch to the “ON” position.
2. Select [DCU] and check if U0100 has been detected.

Has DTC U0100 been detected?