Code No. P0174: Left Bank Abnormal Fuel System (Lean)








OPERATION



  • Refer to Code No. P0202: No. 2 Injector System .
  • Refer to Code No. P0204: No. 4 Injector System .
  • Refer to Code No. P0206: No. 6 Injector System .

FUNCTION



  • If the fuel system goes out of order, the fuel correction value will become larger.
  • The engine-ECU <M/T> or engine-A/T-ECU <A/T> checks whether the fuel trim value is within a specified range.

TROUBLE JUDGMENT


Check Condition
  • In learning the air-fuel ratio.
Judgement Criterion
  • The correction value of fuel injection amount is too high for 10 seconds or more.

PROBABLE CAUSES



  • Failed intake air temperature sensor
  • Failed air flow sensor
  • Failed No. 2, No. 4 and No. 6 injector
  • Air drawn in from gaps in gasket, seals, etc.
  • Failed engine coolant temperature sensor
  • Failed barometric pressure sensor
  • Exhaust leak
  • Incorrect fuel pressure
  • Injector circuit or connector damage
  • Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. Check for exhaust leaks

Q. Is the check result normal?
Go to Step 2 .
Repair.

STEP 2. Check for intake system vacuum leaks.

Q. Is the check result normal?
Go to Step 3 .
Repair.

STEP 3. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item 05: Intake air temperature sensor
  2. Item 06: Engine coolant temperature sensor
  3. Item 08: Manifold absolute pressure sensor
  4. Item 10: Air flow sensor

Q. Are the check results normal?
Go to Step 4 .
Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data value (Refer to Inspection Chart for Diagnosis Code ).

STEP 4. M.U.T.-III data list

  • Refer to Data List Reference Table .

  1. Item BB: Barometric pressure sensor

Q. Is the check result normal?
Go to Step 5 .
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

STEP 5. Connector Check: B-48 injector intermediate connector

Q. Is the check result normal?
Go to Step 6 .
Repair or replace the connector.

STEP 6. Perform resistance measurement at B-48 injector intermediate connector.

  • Disconnect connector, and measure at harness side.

  1. Resistance between terminal No. 2 and No. 8 (No. 2 injector).
  2. Resistance between terminal No. 7 and No. 8 (No. 4 injector).
  3. Resistance between terminal No. 5 and No. 8 (No. 6 injector).
OK: 10.5 - 13.5 (at 20°C)

Q. Is the check result normal?
Go to Step 9 .
Go to Step 7 .

STEP 7. Connector Check: Injector connector

  1. B-111 (No. 2 injector connector).
  2. B-105 (No. 4 injector connector).
  3. B-104 (No. 6 injector connector).

Q. Are the check results normal?
Go to Step 8 .
Repair or replace the connector.

STEP 8. Check No. 2, No. 4 and No. 6 injector itself.

  • Check No. 2, No. 4 and No. 6 injector itself (Refer to ).

Q. Is the check result normal?

    Check and repair harness between injector intermediate connector and injector connector.

  1. Check and repair harness between B-48 (terminal No. 2) injector intermediate connector and B-111 (terminal No. 2) No. 2 injector connector
  2. Check and repair harness between B-48 (terminal No. 7) injector intermediate connector and B-105 (terminal No. 2) No. 4 injector connector
  3. Check and repair harness between B-48 (terminal No. 5) injector intermediate connector and B-104 (terminal No. 2) No. 6 injector connector

  • Check output line for damage.
Replace the injector.

STEP 9. Connector check: D-243 engine-ECU <M/T> connector or D-212 engine-A/T-ECU <A/T> connector

Q. Is the check result normal?
Go to Step 10 .
Repair or replace the connector.

STEP 10. Check harness between injector intermediate connector and engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

  1. Check harness between B-48 (terminal No. 2) injector intermediate connector and D-243 (terminal No. 5) engine-ECU <M/T> connector or D-212 (terminal No. 5) engine-A/T-ECU <A/T> connector.
  2. Check harness between B-48 (terminal No. 7) injector intermediate connector and D-243 (terminal No. 21) engine-ECU <M/T> connector or D-212 (terminal No. 21) engine-A/T-ECU <A/T> connector.
  3. Check harness between B-48 (terminal No. 5) injector intermediate connector and D-243 (terminal No. 6) engine-ECU <M/T> connector or D-212 (terminal No. 6) engine-A/T-ECU <A/T> connector.

  • Check output line for damage.

Q. Are the check results normal?
Go to Step 11 .
Repair the damaged harness wire.

STEP 11. Fuel pressure measurement.

  • Fuel pressure measurement (Refer to ).

Q. Is the check result normal?
Go to Step 12 .
Repair.

STEP 12. Check for entry of foreign matter (water, diesel fuel, etc.) into fuel.

Q. Is the check result normal?
Go to Step 13 .
Replace the fuel.

STEP 13. Replace the No. 2, No. 4 and No. 6 injector.

  • After replacing the injector, re-check the trouble symptoms.

Q. Is the check result normal?
Check end.
Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.