Code No. P0171: Right Bank Abnormal Fuel System (Lean) <Vehicles except for Brazil>

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 <M/T> or engine-A/T-ECU <A/T> checks whether the fuel trim value is within a specified range.

TROUBLE JUDGMENT

Check Conditions

Engine coolant temperature is lower than 100°C when the engine is started.
Intake air temperature is lower than 60°C when the engine is started.
Under the closed loop air/fuel ratio control.
Engine coolant temperature is higher than 76°C.
Air flow sensor output is 8 g/sec or more.

Judgment Criterion

Long-term fuel trim has continued to be higher than +12.5 % for 5 seconds.

Short-term fuel trim has continued to be higher than +7.4 % for 5 seconds.

Check Conditions

Engine coolant temperature is lower than 100°C when the engine is started.
Intake air temperature is lower than 60°C when the engine is started.
Under the closed loop air/fuel ratio control.
Engine coolant temperature is higher than 76°C.
Air flow sensor output is 8 g/sec or less.

Judgment Criterion

Long-term fuel trim has continued to be higher than +12.5 % for 5 seconds.

Short-term fuel trim has continued to be higher than +12.5% for 5 seconds.

Check Conditions

Engine coolant temperature is higher than 100°C when the engine is started.
Intake air temperature is higher than 60°C when the engine is started.
Under the closed loop air/fuel ratio control.
Engine coolant temperature is higher than 76°C.
Air flow sensor output is 8 g/sec or more.

Judgment Criterion

Long-term fuel trim has continued to be higher than +12.5 % for 5 seconds.

Short-term fuel trim has continued to be higher than +17.6 % for 5 seconds.

Check Conditions

Engine coolant temperature is higher than 100°C when the engine is started.
Intake air temperature is higher than 60°C when the engine is started.
Under the closed loop air/fuel ratio control.
Engine coolant temperature is higher than 76°C.
Air flow sensor output is 8 g/sec or less

Judgment Criterion

Long-term fuel trim has continued to be higher than +12.5 % for 5 seconds.

Short-term fuel trim has continued to be higher than +22.3 % 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 than +25.0 % for 2 seconds.

PROBABLE CAUSES

Failed intake air temperature sensor
Failed air flow sensor
Failed No. 1, No. 3 and No. 5 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 .

Item 05: Intake air temperature sensor
Item 06: Engine coolant temperature sensor
Item 08: Manifold absolute pressure sensor
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 .

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-28 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-28 injector intermediate connector.

Disconnect connector, and measure at harness side.

Resistance between terminal No. 7 and No. 8 (No. 1 injector).
Resistance between terminal No. 7 and No. 9 (No. 3 injector).
Resistance between terminal No. 7 and No. 10 (No. 5 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

B-119 (No. 1 injector connector).
B-120 (No. 3 injector connector).
B-121 (No. 5 injector connector).

Q. Are the check results normal?

	Go to Step 8 .

	Repair or replace the connector.

STEP 8. Check No. 1, No. 3 and No. 5 injector itself.

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

Q. Is the check result normal?

Check and repair harness between B-28 (terminal No. 8) injector intermediate connector and B-119 (terminal No. 2) No. 1 injector connector
Check and repair harness between B-28 (terminal No. 9) injector intermediate connector and B-120 (terminal No. 2) No. 3 injector connector
Check and repair harness between B-28 (terminal No. 10) injector intermediate connector and B-121 (terminal No. 2) No. 5 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.

Check harness between B-28 (terminal No. 8) injector intermediate connector and D-243 (terminal No. 1) engine-ECU <M/T> connector or D-212 (terminal No. 1) engine-A/T-ECU <A/T> connector.
Check harness between B-28 (terminal No. 9) injector intermediate connector and D-243 (terminal No. 14) engine-ECU <M/T> connector or D-212 (terminal No. 14) engine-A/T-ECU <A/T> connector.
Check harness between B-28 (terminal No. 10) injector intermediate connector and D-243 (terminal No. 2) engine-ECU <M/T> connector or D-212 (terminal No. 2) 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 Fuel Pressure Test ).

Q. Is the check result normal?

	Go to Step 12 .

	Repair.

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

Q. Is the check result normal?

	Go to Step 13 .

	Replace the fuel.

STEP 13. Replace the B-119, B-120 and B-121 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>.