Front Fog Light Circuit [10/2023 - 11/2024]: Procedure

1. Choose the model to be inspected.

   Result

   Result	Proceed to
   Type A	A
   Type B	B

Result: 

B 

See step  3

Result: 

A 

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	Front fog light relay	OFF or ON	Light control switch in TAIL position

   Body Electrical > Main Body > Active Test 

   Tester Display
   Front Fog Light

   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 [12/2021 - ]

Result: 

NG 

See step  4

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 light relay	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 [12/2021 - ]

Result: 

NG 

See step  4

1. Remove the FOG FR relay.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   5 (FOG FR relay) - Body ground	Ignition switch off	11 to 14 V

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to FOG FR Relay)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Remove the FOG FR relay.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   2 (FOG FR relay) - Body ground	Light control switch in TAIL or HEAD position	11 to 14 V

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to FOG FR Relay)

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  10

Result: 

OK 

See step  6

1. Inspect the FOG FR relay.

   Refer to ON-VEHICLE INSPECTION [02/2019 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FOG FR RELAY 

Result: 

OK 

See step  7

1. *1: except TMMC Made
2. *2: for TMMC Made

1. Remove the FOG FR relay.
2. Disconnect the B11 fog light assembly LH connector.*1
3. Disconnect the B10 fog light assembly RH connector.*1
4. Disconnect the B13 fog light LED LH connector.*2
5. Disconnect the B12 fog light LED RH connector.*2
6. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   EXCEPT TMMC MADE:
   
   

   Tester Connection	Condition	Specified Condition
   3 (FOG FR relay) - B10-2 (B)	Always	Below 1 Ω
   3 (FOG FR relay) - B11-2 (B)	Always	Below 1 Ω
   3 (FOG FR relay) or B10-2 (B) - Body ground	Always	10 kΩ or higher
   3 (FOG FR relay) or B11-2 (B) - Body ground	Always	10 kΩ or higher

   FOR TMMC MADE:
   
   

   Tester Connection	Condition	Specified Condition
   3 (FOG FR relay) - B10-2 (B)	Always	Below 1 Ω
   3 (FOG FR relay) - B11-2 (B)	Always	Below 1 Ω
   3 (FOG FR relay) or B10-2 (B) - Body ground	Always	10 kΩ or higher
   3 (FOG FR relay) or B11-2 (B) - 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 FOG FR relay.
2. Disconnect the 4A instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1 (FOG FR relay) - 4A-52	Always	Below 1 Ω
   1 (FOG FR relay) or 4A-52 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  9

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the instrument panel junction block assembly.

   Refer to REMOVAL [10/2023 - ]

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.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   4A-52 - A-7 (FFGO)	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

Refer to REMOVAL [10/2023 - ]

Result: 

NG 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

Refer to REMOVAL [10/2023 - ]

1. Remove the FOG FR relay.
2. Disconnect the 4F instrument panel junction block assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (FOG FR relay) - 4F-32	Always	Below 1 Ω
   2 (FOG FR relay) or 4F-32 - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

Refer to REMOVAL [10/2023 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR