Part 3

FA20 ENGINE CONTROL: SFI SYSTEM: P0171, P0172, P1170, P117B; System Too Lean (Bank 1); 2013 MY FR-S [03/2012 -]
P0171 - System Too Lean (Bank 1)
P0172 - System Too Rich (Bank 1)
P1170 - Port Injector Fuel Performance
P117B - Direct Injector Fuel Performance
(Continued)

11. CHECK EMISSION CONTROL SYSTEM

(a) Check emission control system Testing and Inspection.

NG -- REPAIR OR REPLACE EMISSION CONTROL SYSTEM
OK -- Continue to next step.

12. CHECK INTAKE SYSTEM

(a) Check the intake system for vacuum leaks Intake System.

OK:

No leaks in intake system.

NG -- REPAIR OR REPLACE INTAKE SYSTEM
OK -- Continue to next step.

13. INSPECT ENGINE COOLANT TEMPERATURE SENSOR

(a) Inspect the engine coolant temperature sensor Testing and Inspection.

NG -- REPLACE ENGINE COOLANT TEMPERATURE SENSOR Removal
OK -- Continue to next step.

14. READ VALUE USING TECHSTREAM (MAF)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Start the engine.

(e) Enter the following menus: Powertrain / Engine / Data List / MAF.

(f) Read MAF with the engine speed at 3000 rpm.

Standard:





NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)
OK -- Continue to next step.

15. CHECK IGNITION SYSTEM

(a) Check the ignition system Testing and Inspection.

NG -- REPAIR OR REPLACE IGNITION SYSTEM
OK -- Continue to next step.

16. CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leaks.

OK:

No gas leaks.

Result:





B -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)

A -- REPAIR OR REPLACE EXHAUST SYSTEM

17. INSPECT AIR FUEL RATIO SENSOR

(a) Inspect the air fuel ratio sensor Air Fuel Ratio Sensor.

NG -- REPLACE AIR FUEL RATIO SENSOR Removal
OK -- Continue to next step.

18. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

(a) Disconnect the air fuel ratio sensor connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for open):





Standard Resistance (Check for short):





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

19. REPLACE AIR FUEL RATIO SENSOR

(a) Replace the air fuel ratio sensor Removal.

NEXT -- Continue to next step.

20. READ VALUE USING TECHSTREAM (SHORT FT #1 AND LONG FT #1)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Start the engine.

(e) Enter the following menus: Powertrain / Engine / Data List / Short FT #1, Long FT #1.

(f) Read the value displayed on the Techstream.

Standard:





HINT
If the trouble occurs during high speed driving, it is possible to take measurements at medium or low speeds by matching the intake air volume to that at the time of the trouble by shifting down.

NG -- CHECK FUEL PRESSURE (LOW PRESSURE SIDE)

OK -- END

21. CHECK FUEL PRESSURE (LOW PRESSURE SIDE)

(a) Check the fuel pressure (low pressure side) Fuel System.

B -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER CONNECTOR CONNECTION)

A -- REPAIR OR REPLACE FUEL SYSTEM (LOW PRESSURE SIDE)