Error code News Shared knowledge

Hino P20B4 Fault Code: Coolant cut off valve – circuit (circuit high)

25/10/2024

Mục lục

Mục lục

TECHNICAL DESCRIPTION

DCU detects malfunctions based on the coolant cut off valve circuit voltage.

Malfunction of coolant cut off valve is detected.

− Starter switch ON. − Coolant cut off valve duty > 0%

Coolant cut off valve voltage = 2.7 V for 0.1 sec.

After having restored to the normal conditions.

MIL: ON

Symptoms on the Vehicle Due to Malfunction: Control will not work properly if the DEF freezes.

Check if the battery voltage is in the normal range.

− Clear all past DTCs. − Check if no DTC is stored after test drive.

− Harness disconnection or short-circuit − Looseness or unsteady contact of connector − Coolant cut off valve malfunction.

Check the connection of the coolant cut off valve connector (Looseness and poor contact). Was any failure found?

Yes – Connect securely, repair if needed. Clear all past DTCs. Check if no DTC is stored after test drive.

No – Go to Step 2.

Set the starter switch to the “LOCK” position.
Remove the connector of the coolant cut off valve.
Use the electrical tester to measure the resistance between the terminals of the coolant cut off valve.

MEASUREMENT CONDITIONS	TESTER CONNECTIONS	STANDARD VALUES
Starter switch: LOCK	Coolant cut off valve connector LDU – LDV	20°C {68°F}: 9.04 – 9.52 Ω

Do the measurements meet the standard value?

Yes – Go to Step 3.

No – Replace the coolant cut off valve. Clear all past DTCs. Check if no DTC is stored after test drive.

Disconnect the DCU 86P connector.
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.

MEASUREMENT CONDITIONS	TESTER CONNECTIONS	STANDARD VALUES
Starter switch: LOCK	DCU 86P vehicle-side connector WMV+ – Ground WMV- – Ground	∞ Ω

Do the measurements meet the standard value?

Yes – Go to Step 4.

No – Repair or replace the harness. Clear all past DTCs. Check if no DTC is stored after test drive.

Connect the coolant cut off valve connector.
Connect the signal check harness and use the electrical tester to measure the resistance between the terminals of the DCU 86P vehicle-side connector.

MEASUREMENT CONDITIONS	TESTER CONNECTIONS	STANDARD VALUES
Starter switch: LOCK	DCU 86P vehicle-side connector WMV+ – WMV-	20°C {68°F}: 9.04 – 9.52 Ω