Code No. P0270: No. 4 Injector Circuit Low Input




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Condition
Judgement Criterion

FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. M.U.T.-III actuator test



  • Item 1: No. 4 injector
OK: Idling state varies.

Q. Is the check result normal?

Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Check No. 4 injector itself.



  • No. 4 Injector connector check.
  • Injector check (Refer to ).

Q. Is the check result normal?

Go to Step 3.
Repair or replace the connector, or replace the No. 4 injector.

STEP 3. Perform voltage measurement at No. 4 injector connector.



  • Disconnect connector, and measure at harness side.
  • Ignition switch: "ON"
  • Voltage between terminal power supply line and body earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 4.

    Repair or replace the connector, or check and repair harness between engine control relay connector terminal and No. 4 injector connector terminal.

    • Check power supply line for open/short circuit.

STEP 4. Check harness between engine control relay connector terminal and No. 4 injector connector terminal.



  • Check power supply line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 5.
Repair or replace the connector, or repair the damaged harness wire.

STEP 5. Check harness between No. 4 injector connector terminal and engine-ECU connector terminal INJ4.



  • Check output line for open/short circuit and damage.

Q. Is the check result normal?

Go to Step 6.
Repair or replace the connector, or repair the damaged harness wire.

STEP 6. Perform signal wave pattern measurement at engine-ECU connector (Using an oscilloscope).



  • Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB992110) to measure at connector for inspection.
  • Engine: Idling
  • Transmission: Neutral <M/T> or P range <CVT>
  • Voltage between terminal INJ4 and body earth.
OK: Waveforms should be displayed on inspection procedure using an oscilloscope (Refer to ).

Q. Is the check result normal?

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