| Symptom of malfunction |
|
| Output limit, etc. | Output limit |
| Malfunction indicator light | Light on |
| Multi information | Engine system failure (red) ↔ Stop the vehicle in the safe area. |
| Possible cause of malfunction | Malfunction of injector solenoid valve drive system common 1 (+B 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.
- Turn the starter key "ON" and measure voltage between the ECU case GND and a terminal of the signal check harness as listed below.
Diagnosis code Terminal subject to resistance measurement DTC code Diagnosis monitor code 68 ECU case GND 68 ECU case GND
ECU terminal No. Description of terminal
Standard value: 1 V or less
NO
Go to [2] Measuring voltage between injector terminals.YES
Go to [3] Measuring resistance between terminals.
- Set the starter key to the "LOCK" position and disconnect the injector harness integrated connector from the cylinder head.
- Turn the starter key ON and measure voltage between the ECU case GND and a terminal of the injector cluster connector (vehicle harness side) as listed below.
Diagnosis code Terminal subject to voltage measurement DTC code Diagnosis monitor code Positive Negative 68 ECU case GND 68 ECU case GND
Standard value: 1 V or less
NO
Faulty harness (short-circuit)YES
Faulty harness in the head cover (short-circuit)
- Set the starter key to the "LOCK" position and measure resistance between the ECU case GND and a terminal of the signal check harness as listed below.
Diagnosis code Terminal subject to resistance measurement DTC code Diagnosis monitor code Positive Negative 68 ECU case GND 68 ECU case GND
Standard value: ∞ Ω
NO
Go to [4] Measuring resistance between injector terminals.YES
Go to [5] Checking the diagnosis code.
- Measure resistance between the ECU case GND and a terminal of the injector cluster connector (vehicle harness side) as listed below.
Diagnosis code Terminal subject to voltage measurement DTC code Diagnosis monitor code Positive Negative 68 ECU case GND 68 ECU case GND
Standard value: ∞ Ω
NO
Faulty harness (short-circuit)YES
Faulty harness in the head cover (short-circuit), faulty injector harness (short-circuit), fault in injector insulation
- Connect the signal check harness connectors to the ECU and start the engine.
- Use the HINO-DX to delete past malfunctions and then check a present malfunction.
- Replace the engine ECU if the same code is output again. If a normal code is output, there may have been some short-lived abnormalities.
- Confirm the DTC P1212 is inactive
- Start the engine and let it idling condition.
- Verify the DTC P1212 is inactive.
- DTC Clear
- Clear the DTC with Hino DX
- Confirm the same DTC is not reoccurred
- P1212 is reoccur: Return to first process
- Other DTC appear: Refer to concerned Trouble shooting
Complete
