Code No. P0172: Right Bank Abnormal Fuel System (rich)








OPERATION



  • Refer to Code No. P0201: No. 1 Injector System .
  • Refer to Code No. P0203: No. 3 Injector System .
  • Refer to Code No. P0205: No. 5 Injector System .

FUNCTION



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

TROUBLE JUDGMENT


Check Conditions
  • Under the closed loop air/fuel ratio control.
  • Engine coolant temperature is higher than 76°C.
  • Air flow sensor output is 12 g/sec or more.
Judgment Criterion
  • Long-term fuel trim has continued to be lower than -12.5 % for 5 seconds.


  • Short-term fuel trim has continued to be lower than -7.4 % for 5 seconds.
Check Conditions
  • Under the closed loop air/fuel ratio control.
  • Engine coolant temperature is higher than 76°C.
  • Air flow sensor output is 12 g/sec or less.
Judgment Criterion
  • Long-term fuel trim has continued to be lower than -12.5 % for 5 seconds.


  • Short-term fuel trim has continued to be lower than -12.5 % for 5 seconds.
Check Conditions
  • Engine coolant temperature is higher than 76°C.
  • Under the closed loop air/fuel ratio control.
Judgment Criterion
  • Long-term fuel trim has continued to be -12.5 % for 2 seconds.


  • Short-term fuel trim has continued to be -50.0 % for 2 seconds.

PROBABLE CAUSES



  • Failed intake air temperature sensor
  • Failed air flow sensor
  • Failed No. 1, No. 3 and No. 5 injector
  • Failed engine coolant temperature sensor
  • Failed manifold absolute pressure sensor
  • Failed barometric pressure sensor
  • Incorrect fuel pressure
  • Failed engine-ECU

DIAGNOSIS PROCEDURE


STEP 1. 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 2 .
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 2. 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 3 .
Replace the engine-ECU.

STEP 3. Connector check: B-44 intermediate connector


Q. Is the check result normal?

Go to Step 4 .
Repair or replace the connector.

STEP 4. Perform resistance measurement at B-44 intermediate connector.



  • Disconnect connector, and measure at harness side.

  1. Resistance between terminal No. 6 and No. 7 (No. 1 injector).
  2. Resistance between terminal No. 6 and No. 8 (No. 3 injector).
  3. Resistance between terminal No. 6 and No. 9 (No. 5 injector).
OK: 10.5 - 13.5 (at 20°C)

Q. Are the check results normal?

Go to Step 6 .
Go to Step 5 .

STEP 5. Check No. 1, No. 3 and No. 5 injector itself.



  • Check No. 1, No. 3 and No. 5 Injector itself (Refer to ).

Q. Are the check results normal?


    Check and repair harness between intermediate connector and injector connector.

  1. Check and repair harness between B-44 (terminal No. 7) intermediate connector and B-102 (terminal No. 2) No. 1 injector connector
  2. Check and repair harness between B-44 (terminal No. 8) intermediate connector and B-105 (terminal No. 2) No. 3 injector connector
  3. Check and repair harness between B-44 (terminal No. 9) intermediate connector and B-127 (terminal No. 2) No. 5 injector connector

  • Check output line for damage.
Replace the injector.

STEP 6. Fuel pressure measurement.



  • Fuel pressure measurement (Refer to Fuel Pressure Test ).

Q. Is the check result normal?

Go to Step 7 .
Repair.

STEP 7. Replace No. 1, No. 3 and No. 5 injectors.



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

Q. Are the check results normal?

Check end.
Replace the engine-ECU.