DTC P0171: System Too Lean (Bank 1); DTC P0172: System Too Rich (Bank 1); DTC P0174: System Too Lean (Bank 2); DTC P0175: System Too Rich (Bank 2) [04/2013 - 08/2015]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTC P0171, P0172, P0174 or P0175 is output	A
   DTC P0171, P0172, P0174 or P0175 and other DTCs are output	B

   HINT: 

   If any DTCs other than P0171, P0172, P0174 or P0175 are output, troubleshoot those DTCs first.

Result: 

B 

GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [04/2013 - 06/2014]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [06/2014 - 08/2015] 

Result: 

A 

See step  2

1. Check the PCV hose connections.

   Refer to COMPONENTS [04/2013 - 08/2015]

   OK

   PCV valve and hose are connected correctly and are not damaged.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE PCV HOSE 

Result: 

OK 

See step  3

1. Check the intake system for vacuum leaks.

   Refer to ON-VEHICLE INSPECTION [04/2013 - 08/2015]

   OK

   No leaks in intake system.

   HINT: 

   • Perform "Inspection After Repair" after repairing or replacing the intake system.

     Refer to INITIALIZATION [04/2013 - 08/2015]

   • If a malfunction is detected while the brake pedal is being depressed, vacuum leaks in the brake booster assembly are suspected. Inspect the brake booster assembly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE INTAKE SYSTEM 

Result: 

OK 

See step  4

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.
5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / Gas AF Control / AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Volume for A/F Sensor

   Data List Display
   AFS Voltage B1S1
   AFS Voltage B2S1
   O2S B1S2
   O2S B2S2

6. Perform the Control the Injection Volume for A/F Sensor operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
7. Monitor the voltage outputs of the air fuel ratio sensor and the heated oxygen sensor (AFS Voltage B1S1 and O2S B1S2 or AFS Voltage B2S1 and O2S B2S2) displayed on the Techstream.

   HINT: 

   • The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%
   • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
   • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

   Standard

   Techstream Display (Sensor)	Injection Volume	Status	Voltage
   AFS Voltage B1S1 AFS Voltage B2S1 (Air fuel ratio)	12.5%	Rich	Below 3.1 V
   	-12.5%	Lean	Higher than 3.4 V
   O2S B1S2 O2S B2S2 (Heated oxygen)	12.5%	Rich	Higher than 0.55 V
   	-12.5%	Lean	Below 0.4 V

   Result

   Status AFS Voltage B1S1 or AFS Voltage B2S1	Status O2S B1S2 or O2S B2S2	Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition	Suspected Trouble Area	Proceed to
   Lean/Rich	Lean/Rich	Normal	-	A
   Lean	Lean	Actual air fuel ratio lean	PCV valve and hose PCV hose connections Fuel injector assembly blockage Gas leak from exhaust system Intake system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor
   Rich	Rich	Actual air fuel ratio rich	Fuel injector assembly leak or blockage Gas leak from exhaust system Ignition system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor
   Lean	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor	B
   Rich	Lean/Rich	Air fuel ratio sensor malfunction	Air fuel ratio sensor

   1. Lean: During Control the Injection Volume for A/F Sensor, the air fuel ratio sensor output voltage (AFS Voltage B1S1 or AFS Voltage B2S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2 or O2S B2S2) is consistently below 0.4 V.
   2. Rich: During Control the Injection Volume for A/F Sensor, the AFS Voltage B1S1 or AFS Voltage B2S1 is consistently below 3.1 V, and the O2S B1S2 or O2S B2S2 is consistently higher than 0.55 V.
   3. Lean/Rich: During Control the Injection Volume for A/F Sensor of the Active Test, the output voltage of the heated oxygen sensor alternates correctly.

   HINT: 

   Refer to "Data List / Active Test" [AFS Voltage B1S1, AFS Voltage B2S1, O2S B1S2 and O2S B2S2].

   Refer to DATA LIST / ACTIVE TEST [04/2013 - 06/2014] , or refer to DATA LIST / ACTIVE TEST [06/2014 - 08/2015]

Result: 

B 

See step  13

Result: 

A 

See step  5

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Coolant Temp.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temp

5. Read the Data List twice, when the engine is both cold and warmed up.

   Standard

   Techstream Display	Condition	Specified Condition
   Coolant Temp	Cold engine	Same as ambient air temperature
   	Warm engine	Between 75 and 100°C (167 and 212°F)

   HINT: 

   Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.

   Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to  REMOVAL [04/2013 - 08/2015] 

Result: 

OK 

See step  6

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / MAF, Coolant Temp and Engine Speed.

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   MAF
   Coolant Temp

5. Allow the engine to idle until Coolant Temp reaches 75°C (167°F) or higher.
6. Read MAF with the engine speed at 3000 rpm.

   Standard

   Techstream Display	Condition	Specified Condition
   MAF	Shift lever position: N A/C: Off Engine Speed: 3000 rpm	Between 7.60 gm/sec and 11.40 gm/sec

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  18

Result: 

OK 

See step  7

1. Check the fuel pressure (low pressure side).

   Refer to PROCEDURE - Step 2

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE FUEL SYSTEM (LOW PRESSURE SIDE) 

Result: 

OK 

See step  8

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Start the engine.
5. Enter the following menus: Powertrain / Engine and ECT / Data List / Gas General / Fuel Press.

   Powertrain > Engine > Data List 

   Tester Display
   Fuel Press

6. While revving the engine, check that the fuel pressure fluctuates.

   Standard

   Idling 

   3500 to 4500 kPag.

   2000 rpm (Depress accelerator pedal fully) 

   7000 to 9000 kPag.

   HINT: 

   The A/C switch and all accessory switches should be off, and the shift lever should be in the N or P position, and the engine should be fully warmed up.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FUEL DELIVERY PIPE SUB-ASSEMBLY (FUEL PRESSURE SENSOR). Refer to  REMOVAL [04/2013 - 08/2015] 

Result: 

OK 

See step  9

1. Check the fuel pressure (high pressure side).

   Refer to PROCEDURE - Step 3

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE FUEL SYSTEM (HIGH PRESSURE SIDE) 

Result: 

OK 

See step  10

1. Check for exhaust gas leaks.

   OK

   No gas leaks.

   HINT: 

   Perform "Inspection After Repair" after repairing or replacing the exhaust system.

   Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE EXHAUST SYSTEM 

Result: 

OK 

See step  11

1. Perform a spark test.

   Refer to PROCEDURE - Step 1

   HINT: 

   • If the result of the spark test is normal, proceed to the next step.
   • Perform "Inspection After Repair" after repairing or replacing the ignition system.

     Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  12

1. Check the injection and volume.

   HINT: 

   • Refer to the fuel injector assembly inspection procedure.

     Refer to INSPECTION [04/2013 - 08/2015]

   • If the fuel injector assemblies malfunction, engine misfire may occur. The misfire count can be read using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Gas Misfire / Cylinder #1 Misfire Count (to Cylinder #6 Misfire Count).
2. Inspect the cold start fuel injector assembly.

   HINT: 

   Perform "Inspection After Repair" after replacing the fuel injector assembly or cold start fuel injector assembly.

   Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  17

Result: 

NG 

REPLACE FUEL INJECTOR ASSEMBLY 

Fuel Injector Assembly: Refer to REMOVAL [04/2013 - 08/2015]

Cold Start Fuel Injector Assembly: Refer to REMOVAL [04/2013 - 08/2015]

Refer to PROCEDURE - Step 1 [04/2013 - 06/2014] , or refer to PROCEDURE - Step 1 [06/2014 - 08/2015]

Result

Result: 

NG 

REPLACE AIR FUEL RATIO SENSOR. Refer to  REMOVAL [04/2013 - 08/2015] 

Result: 

OK 

See step  14

Refer to PROCEDURE - Step 2 [04/2013 - 06/2014] , or refer to PROCEDURE - Step 2 [06/2014 - 08/2015]

Result

Result: 

NG 

See step  23

Result: 

OK 

See step  15

Refer to PROCEDURE - Step 3 [04/2013 - 06/2014] , or refer to PROCEDURE - Step 5 [06/2014 - 08/2015]

Result

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  16

1. Replace the air fuel ratio sensor.

   Refer to REMOVAL [04/2013 - 08/2015]

   HINT: 

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor.

   Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  17

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 08/2015]

   Powertrain > Engine > Clear DTCs 

5. Turn the engine switch off and wait for at least 30 seconds.
6. Turn the engine switch on (IG).
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
11. Read the DTCs.

    Powertrain > Engine > Trouble Codes 

    Result

    Result	Proceed to
    DTC P0171, P0172, P0174 or P0175 is output	A
    DTCs are not output	B

Result: 

B 

END 

Result: 

A 

See step  18

1. Check the connection and terminal contact pressure of connectors and wire harnesses between the mass air flow meter sub-assembly and ECM.

   Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [04/2013 - ]

   HINT: 

   Repair any problems.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  19

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 08/2015]

   Powertrain > Engine > Clear DTCs 

5. Turn the engine switch off and wait for at least 30 seconds.
6. Turn the engine switch on (IG).
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
11. Read the DTCs.

    Powertrain > Engine > Trouble Codes 

    Result

    Result	Proceed to
    DTC P0171, P0172, P0174 or P0175 is output	A
    DTCs are not output	B

Result: 

B 

END 

Result: 

A 

See step  20

Refer to PROCEDURE - Step 3 [04/2013 - 06/2014] , or refer to PROCEDURE - Step 3 [06/2014 - 08/2015]

Result

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  21

1. Replace the mass air flow meter sub-assembly.

   Refer to REMOVAL [04/2013 - 08/2015]

   HINT: 

   • If the result of the inspection performed in step 6 indicated no problem, proceed to the next step without replacing the mass air flow meter sub-assembly.
   • Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.

     Refer to INITIALIZATION [04/2013 - 08/2015]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  22

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 08/2015]

   Powertrain > Engine > Clear DTCs 

5. Turn the engine switch off and wait for at least 30 seconds.
6. Turn the engine switch on (IG).
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
11. Read the DTCs.

    Powertrain > Engine > Trouble Codes 

    Result

    Result	Proceed to
    DTCs are not output	A
    DTC P0171, P0172, P0174 or P0175 is output	B

Result: 

A 

END 

Result: 

B 

REPLACE ECM. Refer to  REMOVAL [04/2013 - 08/2015] 

Refer to PROCEDURE - Step 5 [04/2013 - 06/2014] , or refer to PROCEDURE - Step 5 [06/2014 - 08/2015]

Result

Result: 

OK 

REPLACE SEMICONDUCTOR PWR INTEGRATION ECU. Refer to  REMOVAL [04/2013 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR