Front Fog Light Circuit [10/2018 - 07/2022]: Procedure

1. Check the operation of the taillights.

   OK

   Taillights operate normally.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [10/2018 - 10/2019]  Refer to  PROBLEM SYMPTOMS TABLE [10/2019 - 10/2020]  Refer to  PROBLEM SYMPTOMS TABLE [10/2020 - 07/2022] 

Result: 

OK 

See step  2

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Main Body / Active Test.
5. Perform the Active Test according to the display on the Techstream.

   Body Electrical > Main Body > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Front Fog Light Relay	Front fog lights	OFF or ON	Light control switch in tail position

   Body Electrical > Main Body > Active Test 

   Tester Display
   Front Fog Light Relay

   OK

   Front fog light relay operates. (Front fog lights come on.)

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [10/2018 - 10/2019]  Refer to  PROBLEM SYMPTOMS TABLE [10/2019 - 10/2020]  Refer to  PROBLEM SYMPTOMS TABLE [10/2020 - 07/2022] 

Result: 

NG 

See step  3

1. Disconnect the No. 1 integration relay connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *A	for HV Model
   *B	for Gasoline Model
   *a	Component without harness connected (to No. 1 Integration Relay)

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   FOR HV MODEL
   
   

   Tester Connection	Switch Condition	Specified Condition
   2B-9 - Body ground	Ignition switch off	11 to 14 V

   FOR GASOLINE MODEL
   
   

   Tester Connection	Switch Condition	Specified Condition
   1B-9 - Body ground	Ignition switch off	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Disconnect the No. 1 integration relay connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *A	for HV Model
   *B	for Gasoline Model
   *a	Component without harness connected (to No. 1 Integration Relay)

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   FOR HV MODEL
   
   

   Tester Connection	Condition	Specified Condition
   2B-11 - Body ground	Ignition switch off, Taillights on	11 to 14 V

   FOR GASOLINE MODEL
   
   

   Tester Connection	Condition	Specified Condition
   1B-11 - Body ground	Ignition switch off, Taillights on	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  9

Result: 

OK 

See step  5

1. Remove the No. 1 integration relay from the No. 1 engine room relay block.

   Refer to REMOVAL [10/2018 - 07/2022]

2. Inspect the No. 1 integration relay.

   Refer to INSPECTION [10/2018 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE NO. 1 INTEGRATION RELAY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

OK 

See step  6

1. Disconnect the 2B*1 or 1B*2 No. 1 No. 1 integration relay connector.
   1. *1: for HV Model
   2. *2: for Gasoline Model
2. Disconnect the A23 fog light assembly LH connector.
3. Disconnect the A24 fog light assembly RH connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2B-10 - A23-1 (B)	Always	Below 1 Ω
   2B-11 - A24-1 (B)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  7

1. Disconnect the 4C instrument panel junction block assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   FOR HV MODEL
   
   

   Tester Connection	Condition	Specified Condition
   2B-12 - 4C-25	Always	Below 1 Ω
   2B-12 or 4C-25 - Body ground	Always	10 kΩ or higher

   FOR GASOLINE MODEL
   
   

   Tester Connection	Condition	Specified Condition
   1B-12 - 4C-25	Always	Below 1 Ω
   1B-12 or 4C-25 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [10/2018 - 07/2022]

2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   -

   -

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4C-25 - MB-7 (FFGO)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

1. Disconnect the 2B*1 or 1B*2 No. 1 No. 1 integration relay connector.
   1. *1: for HV Model
   2. *2: for Gasoline Model
2. Disconnect the 4C instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   FOR HV MODEL
   
   

   Tester Connection	Condition	Specified Condition
   2B-11 - 4C-32	Always	Below 1 Ω
   2B-11 or 4C-32 - Body ground	Always	10 kΩ or higher

   FOR GASOLINE MODEL
   
   

   Tester Connection	Condition	Specified Condition
   1B-11 - 4C-32	Always	Below 1 Ω
   1B-11 or 4C-32 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR