DTC P0171-00: System Too Lean Bank 1; DTC P0172-00: System Too Rich Bank 1; DTC P1170-00: Fuel Performance/Port Injector; DTC P117B-00: Fuel Performance/Direct Injector [11/2023 - ]: Procedure

1. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 is output	A
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 and other DTCs are output	B

   HINT: 

   If any DTCs other than P0171-00, P0172-00, P1170-00 and/or P117B-00 are output, troubleshoot those DTCs first.

Result: 

B 

GO TO DTC CHART  . Refer to DIAGNOSTIC TROUBLE CODE CHART [11/2023 - 11/2024] , or refer to DIAGNOSTIC TROUBLE CODE CHART [11/2024 - ]

Result: 

A 

See step  2

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Port.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Short FT B1S1
   Long FT B1S1

   OK

   GTS Display	Specified Condition
   Total of Short FT B1S1 and Long FT B1S1	Between -20 and 20%

4. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Short FT B1S1
   Long FT B1S1

   OK

   GTS Display	Specified Condition
   Total of Short FT B1S1 and Long FT B1S1	Between -20 and 20%

   Result

   Item		Proceed to
   Port	Direct
   OK	OK	A
   OK	NG	B
   NG	OK	C
   NG	NG	D

Result: 

B 

See step  4

Result: 

C 

See step  11

Result: 

D 

See step  12

Result: 

A 

See step  3

1. Has the vehicle run out of fuel in the past?

   Result

   Proceed to
   YES
   NO

Result: 

YES 

DTC CAUSED BY RUNNING OUT OF FUEL 

Result: 

NO 

CHECK FOR INTERMITTENT PROBLEMS 

Refer to CHECK FOR INTERMITTENT PROBLEMS [12/2019 - ]

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. According to the display on the GTS, read the Data List.

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   Fuel Pressure (High)
   Injection Mode

   HINT: 

   During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed.

   Standard

   GTS Display	Condition	Specified Condition
   Fuel Pressure (High)	Shift position: P A/C: Off Engine warmed up Engine Speed: 2500 rpm Injection Mode: Direct	3000 to 25000 kPa

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  7

Result: 

OK 

See step  5

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   High Pressure Fuel Pump Duty Ratio (D4)
   Injection Mode
   Short FT B1S1
   Long FT B1S1

   HINT: 

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

   Result

   Item			Proceed to
   Injection Mode	High Pressure Fuel Pump Duty Ratio (D4)	Total of Short FT B1S1 and Long FT B1S1
   Direct	10 to 50%	-	A
   	50% or higher	-20% or less	B
   	10% or less	+20% or higher
   	50% or higher	+20% or higher	C
   	10% or less	-20% or less	D

   HINT: 

   Perform "Inspection After Repair" after replacing the fuel pressure sensor (for high pressure side).

   Refer to INITIALIZATION [10/2021 - ]

Result: 

B 

REPLACE FUEL PRESSURE SENSOR (FOR HIGH PRESSURE SIDE) 

Refer to REMOVAL [11/2023 - ]

Result: 

C 

See step  8

Result: 

D 

REPLACE ECM 

Refer to REMOVAL [11/2023 - ]

Result: 

A 

See step  6

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   High Pressure Fuel Pump Duty Ratio (D4)
   Injection Mode
   Short FT B1S1
   Long FT B1S1

   HINT: 

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

   Result

   Item			Proceed to
   Injection Mode	High Pressure Fuel Pump Duty Ratio (D4)	Total of Short FT B1S1 and Long FT B1S1
   Direct	10 to 50%	-25% or less	A
   	10 to 50%	+25% or higher
   	10 to 50%	-25 to +25%	B

   HINT: 

   Perform "Inspection After Repair" after replacing the direct fuel injector assembly.

   Refer to INITIALIZATION [10/2021 - ]

Result: 

A 

REPLACE DIRECT FUEL INJECTOR ASSEMBLY 

Refer to REMOVAL [11/2023 - ]

Result: 

B 

CHECK FOR INTERMITTENT PROBLEMS 

Refer to CHECK FOR INTERMITTENT PROBLEMS [12/2019 - ]

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. According to the display on the GTS, read the Data List with the Active Test "Control the Injection Mode" set to Direct.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the Injection Mode

   Data List Display
   Injection Mode
   Misfire Count Cylinder #1
   Misfire Count Cylinder #2
   Misfire Count Cylinder #3
   Misfire Count Cylinder #4

   HINT: 

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

   Result

   Injection Mode	Misfire Count	Proceed to
   Direct	No misfire counts, or misfire counts occur randomly in all cylinders	A
   	Misfire counts occur in particular cylinder	B

   HINT: 

   Perform "Inspection After Repair" after replacing the direct fuel injector assembly.

   Refer to INITIALIZATION [10/2021 - ]

Result: 

B 

REPLACE DIRECT FUEL INJECTOR ASSEMBLY 

Refer to REMOVAL [11/2023 - ]

Result: 

A 

See step  8

Refer to REMOVAL [11/2023 - ]

HINT: 

Perform "Inspection After Repair" after replacing the fuel pump assembly (for high pressure side).

Refer to INITIALIZATION [10/2021 - ]

Result

Result: 

NEXT 

See step  9

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

2. Turn the ignition switch off and wait for at least 30 seconds.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  10

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 is output	B

Result: 

A 

END 

Result: 

B 

REPLACE ECM 

Refer to REMOVAL [11/2023 - ]

1. Check the injection volume (whether fuel volume is high or low, and whether injection pattern is poor).

   Refer to INSPECTION [12/2019 - ]

   HINT: 

   Perform "Inspection After Repair" after replacing the port fuel injector assembly.

   Refer to INITIALIZATION [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM 

Refer to REMOVAL [11/2023 - ]

Result: 

NG 

REPLACE PORT FUEL INJECTOR ASSEMBLY 

Refer to REMOVAL [11/2023 - ]

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Check the PCV hose connections.
2. Check the PCV valve.

   Refer to INSPECTION [12/2019 - ]

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE PCV VALVE OR HOSE 

Result: 

OK 

See step  13

1. Check the intake system for vacuum leaks.

   Refer to ON-VEHICLE INSPECTION [12/2019 - ]

   OK

   No leaks in intake system.

   HINT: 

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

   Refer to INITIALIZATION [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE INTAKE SYSTEM 

Result: 

OK 

See step  14

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. Idle the engine for 5 minutes or more with the shift lever in P.
4. Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.

   Powertrain > Engine > Active Test 

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

   Data List Display
   A/F (O2) Sensor Current B1S1
   A/F (O2) Sensor Current B1S2

5. Monitor the output values of the air fuel ratio sensor (sensor 1) and air fuel ratio sensor (sensor 2) (A/F (O2) Sensor Current B1S1 and A/F (O2) Sensor Current B1S2) displayed on the GTS.

   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 (sensor 1) has an output delay of a few seconds and the air fuel ratio sensor (sensor 2) has a maximum output delay of approximately 20 seconds.
   • If the sensor output value does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

   Standard

   GTS Display (Sensor)	Injection Volume	Status	Voltage
   A/F (O2) Sensor Current B1S1 (Air fuel ratio (sensor 1))	12.5%	Rich	Below -0.075 mA
   	-12.5%	Lean	More than 0.037 mA
   A/F (O2) Sensor Current B1S2 (Air fuel ratio (sensor 2))	12.5%	Rich	Below -0.86 mA
   	-12.5%	Lean	More than 0.33 mA

   Result

   Status A/F (O2) Sensor Current B1S1	Status A/F (O2) Sensor Current B1S2	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 Gas leak from exhaust system Intake system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor EGR valve assembly
   Rich	Rich	Actual air fuel ratio rich	Gas leak from exhaust system Ignition system Fuel pressure Mass air flow meter sub-assembly Engine coolant temperature sensor EGR valve assembly
   Lean	Lean/Rich	Air fuel ratio sensor (sensor 1) malfunction	Air fuel ratio sensor (sensor 1)	B
   Rich	Lean/Rich	Air fuel ratio sensor (sensor 1) malfunction	Air fuel ratio sensor (sensor 1)

   1. Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently more than 0.037 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently more than 0.33 mA.
   2. Rich: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor (sensor 1) output current (A/F (O2) Sensor Current B1S1) is consistently below -0.075 mA, and the air fuel ratio sensor (sensor 2) output current (A/F (O2) Sensor Current B1S2) is consistently below -0.86 mA.
   3. Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output current of the air fuel ratio sensor (sensor 1) or air fuel ratio sensor (sensor 2) alternate correctly.

   HINT: 

   Refer to "Data List / Active Test" [A/F (O2) Sensor Current B1S1 and A/F (O2) Sensor Current B1S2].

   Refer to DATA LIST / ACTIVE TEST [11/2023 - 11/2024] , or refer to DATA LIST / ACTIVE TEST [11/2024 - ]

Result: 

B 

See step  24

Result: 

A 

See step  15

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

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

   Standard

   GTS Display	Condition	Specified Condition
   Coolant Temperature	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 [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE ENGINE COOLANT TEMPERATURE SENSOR 

Refer to REMOVAL [11/2023 - ]

Result: 

OK 

See step  16

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

   HINT: 

   The A/C switch and all accessories should be off.

3. Confirm that the value of Data List item Engine Independent is "Operate" then check the value of Intake Manifold Absolute Pressure while performing the Active Test.

   Powertrain > Engine > Active Test 

   Active Test Display
   Control the EGR Step Position

   Data List Display
   Intake Manifold Absolute Pressure
   Engine Independent

   NOTE:

   • Do not leave the EGR valve open for 10 seconds or more during the Active Test.
   • Be sure to return the EGR valve to step 0 when the Active Test is completed.
   • Do not open the EGR valve 30 steps or more during the Active Test.

   OK

   The value of Intake Manifold Absolute Pressure changes in response to the EGR step position when the value of Engine Independent is "Operate".

   Standard

   -	Control the EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Intake Manifold Absolute Pressure (Data List)	(EGR valve is fully closed)	Intake Manifold Absolute Pressure value is at least +10 kPa (1.45 psi) higher than when EGR valve is fully closed

   HINT: 

   • If the value of Data List item Engine Independent is "Not Opr" when the engine is idling, charge control is being performed. Perform the Active Test after charge control is complete ("Operate" is displayed).
   • While performing the Active Test, if the increase in the value of Intake Manifold Absolute Pressure is small, the EGR valve assembly may be malfunctioning.
   • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of Intake Manifold Absolute Pressure may occur while performing the Active Test. However, the amount that the value of Intake Manifold Absolute Pressure increases will be smaller than normal.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

See step  18

Result: 

NG 

See step  17

1. Remove the EGR valve assembly.

   Refer to REMOVAL [11/2023 - ]

2. Check if the EGR valve is stuck open.

   OK

   EGR valve is tightly closed.

   HINT: 

   Perform "Inspection After Repair" after replacing the EGR valve assembly.

   Refer to INITIALIZATION [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE EGR VALVE ASSEMBLY 

Refer to REMOVAL [11/2023 - ]

Result: 

OK 

See step  18

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. Read Mass Air Flow Sensor while maintaining an engine speed of 2500 rpm.

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   Mass Air Flow Sensor

   HINT: 

   During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed.

   Standard

   GTS Display	Condition	Specified Condition
   Mass Air Flow Sensor	Engine warmed up Shift position: P A/C: Off Engine Speed: 2500 rpm	Between 6.2 and 18.6 gm/sec

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  31

Result: 

OK 

See step  19

Refer to PROCEDURE - Step 2

Result

Result: 

NG 

See step  23

Result: 

OK 

See step  20

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 [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE EXHAUST SYSTEM 

Result: 

OK 

See step  21

Refer to PROCEDURE - Step 3

HINT: 

Perform "Inspection After Repair" after replacing the spark plug.

Refer to INITIALIZATION [10/2021 - ]

Result

Result: 

NG 

REPLACE SPARK PLUG 

Refer to PROCEDURE - Step 3

Result: 

OK 

See step  22

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 replacing the spark plug or ignition coil assembly.

     Refer to INITIALIZATION [10/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  31

Check the fuel lines for leaks or blockage.

Result

Result: 

OK 

GO TO FUEL PUMP CONTROL CIRCUIT 

Refer to Fuel Pump Control Circuit [10/2021 - 11/2024] , or refer to Fuel Pump Control Circuit [11/2024 - ]

Result: 

NG 

REPAIR OR REPLACE FUEL SYSTEM 

Refer to INSPECTION [12/2019 - ]

HINT: 

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

Refer to INITIALIZATION [10/2021 - ]

Result

Result: 

NG 

REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

Refer to REMOVAL [12/2019 - ]

Result: 

OK 

See step  25

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the air fuel ratio sensor (sensor 1) connector.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   C45-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  34

Result: 

OK 

See step  26

1. Disconnect the air fuel ratio sensor (sensor 1) connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C45-1 (HA1A) - C55-9 (HA1A)	Always	Below 1 Ω
   C45-3 (A1A+) - C55-95 (A1A+)	Always	Below 1 Ω
   C45-4 (A1A-) - C55-94 (A1A-)	Always	Below 1 Ω
   C45-1 (HA1A) or C55-9 (HA1A) - Body ground and other terminals	Always	10 kΩ or higher
   C45-3 (A1A+) or C55-95 (A1A+) - Body ground and other terminals	Always	10 kΩ or higher
   C45-4 (A1A-) or C55-94 (A1A-) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  27

Refer to REMOVAL [12/2019 - ]

HINT: 

Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

Refer to INITIALIZATION [10/2021 - ]

Result

Result: 

NEXT 

See step  28

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

2. Turn the ignition switch off and wait for at least 30 seconds.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  29

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 is output	B

Result: 

A 

END 

Result: 

B 

See step  30

1. Put the engine in Inspection Mode (Maintenance Mode).

   Powertrain > Hybrid Control > Utility 

   Tester Display
   Inspection Mode

2. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

   Powertrain > Engine > Data List 

   Tester Display
   Coolant Temperature

3. Read Mass Air Flow Sensor while maintaining an engine speed of 2500 rpm.

   Powertrain > Engine > Data List 

   Tester Display
   Engine Speed
   Mass Air Flow Sensor

   HINT: 

   During charge control, the engine speed is set at idle. Therefore, the engine speed will not increase when the accelerator pedal is depressed. In this case, read the Data List after charge control has completed.

   Standard

   GTS Display	Condition	Specified Condition
   Mass Air Flow Sensor	Engine warmed up Shift position: P A/C: Off Engine Speed: 2500 rpm	Between 6.2 and 18.6 gm/sec

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  31

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 [12/2019 - ]

   HINT: 

   Repair any problems.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  32

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

2. Turn the ignition switch off and wait for at least 30 seconds.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  33

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 is output	B

Result: 

A 

END 

Result: 

B 

See step  38

Refer to PROCEDURE - Step 2

Result

Result: 

NG 

REPLACE EFI-MAIN NO. 2 RELAY 

Result: 

OK 

See step  35

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   3 (EFI-MAIN NO. 2 relay) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 2 RELAY) 

Result: 

OK 

See step  36

1. Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (EFI-MAIN NO. 2 relay) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  37

1. Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.
2. Disconnect the air fuel ratio sensor (sensor 1) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   5 (EFI-MAIN NO. 2 relay) - C45-2 (+B)	Always	Below 1 Ω
   5 (EFI-MAIN NO. 2 relay) or C45-2 (+B) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - EFI-MAIN NO. 2 RELAY) 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the mass air flow meter sub-assembly connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C30-3 (VCC) - C55-78 (VCVG)	Always	Below 1 Ω
   C30-1 (FG) - C55-101 (VG)	Always	Below 1 Ω
   C30-2 (E2G) - C55-79 (E2G)	Always	Below 1 Ω
   C30-3 (VCC) or C55-78 (VCVG) - Body ground and other terminals	Always	10 kΩ or higher
   C30-1 (FG) or C55-101 (VG) - Body ground and other terminals	Always	10 kΩ or higher
   C30-2 (E2G) or C55-79 (E2G) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  39

Refer to ON-VEHICLE INSPECTION [12/2019 - ]

Result

Result: 

NEXT 

See step  40

1. Clear the DTCs.

   Powertrain > Engine > Clear DTCs 

2. Turn the ignition switch off and wait for at least 30 seconds.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  41

1. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
2. Read the DTCs.

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTC P0171-00, P0172-00, P1170-00 and/or P117B-00 is output	B

Result: 

A 

END 

Result: 

B 

REPLACE ECM 

Refer to REMOVAL [11/2023 - ]