Here is a illustration show the guide on how to diagnostics and repair for HINO 600 series 15MY DCU Doser 500 malfunction of DEF injector low.
Preparations:
2024.03 HINO Diagnostic Explorer DX3/DX2 Diagnostic Software Free Download
HINO Trucks EPC Electronic Parts Catalog 2018 2016 Free Download
Procedures:
Step 1:Inspect for short-circuit in the DEF injector harness
Check the connection of the DEF injector connector (Looseness and poor contact).
Was any failure found?
Yes,connect securely,repair if needed.
Perform “After-inspection work” of INFORMATION section
No,go to step2
Step 2:Inspect the DEF injector unit
1.Set the starter switch to the “LOCK” position.
2.Disconnect the DEF injector connector.
3.Use the electrical tester to measure the resistance between the terminals of the DEF injector.
Measuring condition:starter switch lock
Measurement area:DEF injector DML-DMH
Standard value:20°C {68°F}:11.4 – 12.6Ω
Do the measurements meet the standard value?
Yes,go to step 3
No,replace the DEF injector.
Perform “After-inspection work” of INFORMATION section
Step 3:Inspect for short-circuit in the DEF injector harness
1.Disconnect the DCU 86P connector.
2.Connect the signal check harness and use the electrical tester to measure the resistance between the terminals of the DCU 86P vehicle-side connector and the ground.
Measuring condition:Starter switch: LOCK
Measurement area:DCU 86Pvehicle-side connector,DML- Ground,DMH- Ground
Standard value:∞Ω
Do the measurements meet the standard value?
Yes,go to step4
No,repair or replace the harness.
Perform “After-inspection work” of INFORMATION section
Step 4:Inspect disconnection of the DEF injector harness
1.Connect the DEF injector connector.
2.Connect the signal check harness and use the electrical tester to measure the resistance between the terminals of the DCU 86P vehicle-side connector.
Measuring condition:Starter switch: LOCK
Measurement area:DCU 86P vehicle-side connector,DML,DMH
Standard value:20°C {68°F}:11.4 – 12.6Ω
Do the measurements meet the standard value?
Yes,go to step5
No,repair or replace the harness.
Perform “After-inspection work” of INFORMATION section
Step 5:Check the DTG detected (DCU)
1.Perform an engine warm-up. (Water temperature: 60 °C {140 °F} or more)
2.Stop the engine and set the starter switch to the “LOCK” position.
3.Connect the vehicle to HINO DXⅡ
4.Set the starter switch to the “ON” position.
5.Select [DCU] and check if P2048 has been detected.
Has DTC P2048 detected?
Yes,replace the DCU (Perform DPR forced regeneration after replacement)
Perform “After-inspection work” of INFORMATION section
No,procedure completed
Perform “After-inspection work” of INFORMATION section
More case for HINO please refer to:HINO Trouble Repair.