Code No. P0301: No. 1 Cylinder Injector Malfunction (No Injection)

FUNCTION

The engine-ECU, by monitoring the variation in the engine revolution, detects the non-fuel injection state.

TROUBLE JUDGMENT

Check Conditions

During the normal engine operation
Engine coolant temperature is 80°C or higher.
Crank angle sensor is normal.

Judgment Criterion

The variation in the engine revolution is more than the specified value.

FAIL-SAFE AND BACKUP FUNCTION

The DPF regeneration is prohibited.
The EGR control is stopped (fully closed).
The throttle valve is opened (Electrical discontinuity).
The AS&G control is prohibited.

PROBABLE CAUSES

Failed No. 1 injector
No. 1 fuel injection pipe clogged
Improper compression pressure
Failed engine-ECU

DIAGNOSIS PROCEDURE

caution

A high-tension voltage is flowing between the engine-ECU and the injectors while the engine is running. Handle them carefully to avoid receiving electric shocks from the voltage.

STEP 1. M.U.T.-III diagnosis code

After erasing the diagnosis code through M.U.T.-III, operate the engine in the warm-up state and confirm whether the diagnosis code is set.

Q. Is the diagnosis code set?

	Go to Step 2.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 2. Check for No. 1 fuel injection pipe clogged

Remove the No. 1 fuel injection pipe.
Check whether No. 1 fuel injection pipe is clogged or not.

Q. Is it clogged?

	Clean or replace the No. 1 fuel injection pipe.

	Go to Step 3.

STEP 3. Diagnosis code set check after replacing injector.

To determine whether the No. 1 cylinder injector malfunctions or not, temporarily replace the No. 1 cylinder injector with another cylinder injector.
After erasing the diagnosis code through M.U.T.-III, operate the engine in the warm-up state and confirm whether the diagnosis code is set. If the other codes except P0301 is set, the No. 1 cylinder injector should malfunction.

Q. Is diagnosis code P0301 set?

	Go to Step 4.

	Replace the No. 1 injector. After replacing the injector, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions before Service - What The Common Rail Engine Learns <4N1> ). Then go to Step 5 .

STEP 4. Check compression pressure.

Check compression pressure (Refer to GROUP 11E - On-vehicle Service - Compression Pressure Check ).

Q. Is the check result normal?

	Go to Step 5.

	Check and repair the engine itself.

STEP 5. M.U.T.-III diagnosis code

After erasing the diagnosis code through M.U.T.-III, operate the engine in the warm-up state and confirm whether the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the engine-ECU.

	The check is end.