Front Fog Light does not Illuminate: Procedure

1. Using the Techstream, read the Data List.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Front Fog Light SW	Front fog light switch signal/ON or OFF	ON: Front fog light switch on OFF: Front fog light switch off	-

   OK

   When headlight dimmer switch operation is performed, the result will be the same as above.

NG → See step   3 

OK: Go to next step 

1. Using the Techstream, perform the Active Test.
   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Front Fog Light Relay	Front fog light	OFF/ON	-

   OK

   Fog light turns on/off.

NG → See step   5 

OK → REPLACE MAIN BODY ECU 

1. Remove the headlight dimmer switch. Refer to INSPECTION .
   Fig 1: Inspecting Headlight Dimmer Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   4 (BFG) - 3 (LFG)	Headlight dimmer switch (Front fog light switch) on	Below 1 Ω
   	Headlight dimmer switch (Front fog light switch) off	10 kΩ or higher

NG → See step   9 

OK: Go to next step 

1. Disconnect the E14 switch connector.
   Fig 2: Identifying E14 Switch Connector And E2 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the E2 ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E14-4 (BFG) - E2-28 (FFOG)	Always	Below 1 Ω
   E14-3 (LFG) - Body ground
   E14-4 (BFG) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU 

1. Remove the FR FOG relay from the engine room relay block, junction block.
   Fig 3: Identifying Fog Light Relay Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Battery voltage not applied to terminals 1 and 2	10 kΩ or higher
   	Battery voltage applied to terminals 1 and 2	Below 1 Ω

NG → REPLACE FOG LIGHT RELAY (FR FOG) 

OK: Go to next step 

1. Remove the FR FOG relay from the engine room relay block.
   Fig 4: Identifying FR FOG Relay

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   FR FOG relay terminal 2 - Body ground	Light control switch tail	11 to 14 V
   FR FOG relay terminal 5 - Body ground	Always

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

Fig 5: Identifying B1 And B2 Light Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the FR FOG relay from the engine room relay block.
2. Disconnect the B1 and B2 light connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   for LH 

   for RH 

   Tester Connection	Condition	Specified Condition
   FR FOG relay terminal 3 - B1-1	Always	Below 1 Ω
   B1-2 - Body ground
   B1-1 - Body ground	Always	10 kΩ or higher

   Tester Connection	Condition	Specified Condition
   FR FOG relay terminal 3 - B2-1	Always	Below 1 Ω
   B2-2 - Body ground
   B2-1 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the E1 ECU connector.
   Fig 6: Identifying E1 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a service wire, connect terminal E1-4 (FFGO) on the wire harness side and the body ground.
3. Check that the front fog light illuminates.

   OK

   Front fog light illuminates.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (FOG LIGHT RELAY - MAIN BODY ECU) 

OK → REPLACE MAIN BODY ECU