Code No. P0170: Abnormal Fuel System (Cylinder 1, 4)

OPERATION

Refer to Code No. P0201: No. 1 Injector System .
Refer to Code No. P0204: No. 4 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

Judgment Criteria

Long-term fuel trim has continued to be +12.5% or higher for 10 seconds.

or

Long-term fuel trim has continued to be -12.5% or lower for 10 seconds.

PROBABLE CAUSE

Failed intake air temperature sensor
Failed air flow sensor
Failed purge control solenoid valve
Failed injector
Air drawn in from gaps in gasket, seals, etc.
Failed engine coolant temperature sensor
Failed barometric pressure sensor
Exhaust leak
Incorrect fuel pressure
Failed engine-ECU <M/T>
Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

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

Q. Is any other diagnosis code than P0170 output?

	Inspection chart for diagnosis code (Refer to ).

	Go to Step 2 .

STEP 2. M.U.T.-III data list

Refer to Data List Reference Table .

Item 12: Air flow sensor
Item 13: Intake air temperature sensor
Item 21: Engine coolant temperature sensor

Q. Are the check results normal?

	Go to Step 3 .

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

Refer to Data List Reference Table .

Item 25: Barometric pressure sensor

Q. Is the check result normal?

	Go to Step 4 .

	Replace engine-ECU <M/T> or engine-A/T-ECU <A/T>.

STEP 4. Check throttle body (throttle valve portion) for contamination.

Q. Is the check result normal?

	Go to Step 5 .

	Clean throttle body (throttle valve portion) (Refer to ).

STEP 5. Check for intake of air from intake hose and inlet manifold.

Q. Is the check result normal?

	Go to Step 6 .

	Repair.

STEP 6. Check for leakage of exhaust emission from exhaust manifold.

Q. Is the check result normal?

	Go to Step 7 .

	Repair.

STEP 7. Connector Check: Injector connector

B-101 (No. 1 injector connector).
B-105 (No. 4 injector connector).

Q. Are the check results normal?

Go to Step 8 .

Repair or replace.

STEP 8. Check No. 1 and No. 4 injector itself.

Check No. 1 and No. 4 Injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 9 .

	Replace injector.

STEP 9. Connector check: B-15X engine control relay connector and C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector

Q. Is the check result normal?

Go to Step 10 .

Repair or replace.

STEP 10. Check harness between B-15X engine control relay connector and injector connector.

Check intermediate connector C-116, and repair if necessary If intermediate connector is normal, harness between B-15X (terminal No. 1) engine control relay connector and B-101 (terminal No. 1) No. 1 injector connector.
Check intermediate connector C-116, and repair if necessary If intermediate connector is normal, harness between B-15X (terminal No. 1) engine control relay connector and B-105 (terminal No. 1) No. 4 injector connector.

Check power supply line for damage.

Q. Are the check results normal?

Go to Step 11 .

Repair or replace.

STEP 11. Check harness between injector connector and C-110 engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

Check harness between B-101 (terminal No. 2) No. 1 injector connector and C-110 (terminal No. 1) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.
Check harness between B-105 (terminal No. 2) No. 4 injector connector and C-110 (terminal No. 21) engine-ECU <M/T> connector or engine-A/T-ECU <A/T> connector.

Check power supply line for damage.

Q. Are the check results normal?

Go to Step 12 .

Repair.

STEP 12. Check purge control solenoid valve itself.

Check purge control solenoid valve itself (Refer to GROUP 17 - Emission Control System - Evaporative Emission Control System- Purge Control Solenoid Valve ).

Q. Is the check result normal?

	Go to Step 13 .

	Replace purge control solenoid valve.

STEP 13. Fuel pressure measurement.

Fuel pressure measurement (Refer to Fuel Pressure Test ).

Q. Is the check result normal?

	Replace engine-ECU <M/T> or engine-A/T-ECU <A/T>.

	Repair.