This instruction show you guide on how to diagnose HINO 600 series 15MY truck P068A trouble code.
Preparations:
2024.03 HINO Diagnostic Explorer DX3/DX2 Diagnostic Software Free Download
HINO Trucks EPC Electronic Parts Catalog 2018 2016 Free Download
P068A:Abnormality in main relay shut off control
Step 1:Check the DTC detected (DCU)
1.Connect the vehicle to HINO DX2.
2.Set the starter switch to the “ON” position.
3.Select [DCU] and check if any DTC other than P068A (for example, P0562) has been detected.
NOTICE
If the battery switch is turned OFF or a battery terminal is disconnected during the DCU shutdown process, Diagnostic Code P068A may be detected.
Has a DTC other than P068A been detected?
Yes,go to diagnosis procedure of a related DTC
No,go to step 2
Step 2:Inspect the DCU power supply circuit
1.Set the starter switch to the “LOCK” position.
2.Disconnect the DCU 53P connector.
3.Set the starter switch to the “ON” position.
4.Use the electrical tester to measure the voltage between the terminals of the DCU 53P connector (Engine sub harness side) and battery minus (BAT-).
Do the measurements meet the standard value?
Yes,go to step 3
No,repair or replace the battery power supplying circuit (harness,fuse etc.)
Perform “After-inspection work”
Step 3:Inspect the DCU Harness
1.Set the starter switch to the “LOCK” position.
2.Disconnect the connector between the cab main harness and the chassis front harness.
3.Using the electrical tester, measure the resistance between the terminals from the DCU 53P chassis side connector to the chassis side connector of the cab main harness connector to chassis front harness connector.
Do the measurements meet the standard value?
Yes,reconnect DCU 53P connector and cab main harness connector.Go to step 4
No,repair or replace the battery power supplying circuit (harness)
Perform “After-inspection work”
Step 4:Check the DTC detected (DCU)
1.Connect the vehicle to HINO DXⅡ.
2.Set the starter switch to the “ON” position.
3.Erase the malfunction history using HINO DXⅡ.
4.Start the engine.
5.Select [DCU] and check if P068A has been detected.
6.Turn the starter switch OFF while still connected to HINO DXⅡ.
7.After checking that the communication between the HINO DXⅡ and the DCU has been disconnected, turn the starter switch ON again.
8.Select [DCU] and check if P068A has been detected.
Has P068A been detected?
Yes,Replace the DCU.Confirm DCU is programmed to lasted software level
Perform “After-inspection work”
No,Procedures completed.
Perform “After-inspection work”
More case for HINO please refer to:HINO Trouble Repair.