| Symptom of malfunction | Startability may be poor during cooling. |
| Output limit, etc. | Without |
| Malfunction indicator light | Light out |
| Multi information | Preheater failure |
| Possible cause of malfunction | Malfunction of preheating system (open/GND short-circuit) |
Detail
- Set the starter key to the "LOCK" position and connect the signal check harness.
- Disconnect the signal check harness connectors from the ECU and measure resistance between the terminals V23 and V24.
ECU terminal No. Description of terminal
Standard value: 22.5-27.5 Ω
NO
Go to [2] Measuring resistance between relay terminals.
YES
Fault in engine ECU and/or ECU connectors
- Disconnect the heater relay connector.
- Measure resistance between the 1st and 2nd terminals of the heater relay connector (component side).
Standard value: 24-25.6 Ω
NO
Fault in heater relay
YES
Fault in harness and/or connector
- Confirm the DTC P0540 is inactive
- Start the engine and let it idling condition.
- Verify the DTC P0540 is inactive.
- DTC Clear
- Clear the DTC with Hino DX
- Confirm the same DTC is not reoccurred
- P0540 is reoccur: Return to first process
- Other DTC appear: Refer to concerned Trouble shooting
Complete
