Light Control Switch Circuit: Wiring Diagram

1. Check the DATA LIST for proper functioning of the engine room No. 2 relay block.

   Engine room No. 2 relay block 

   ENGINE ROOM RELAY BLOCK SPECIFICATION
   
   

   Item	Measurement Item / Display (Range)	Normal Condition	Diagnostic Note
   F FOG LIGHT SW	Front fog light switch signal / ON or OFF	ON: Front fog light switch is in ON position OFF: Front fog light switch is not in ON position	-
   DIMMER HI SW	High beam switch signal / ON or OFF	ON: Headlight dimmer switch is in HI position OFF: Headlight dimmer switch is not in HI position	-
   LIGHT AUTO	SW Auto light switch signal / ON or OFF	ON: Light control switch is in AUTO position OFF: Light control switch is not in AUTO position	-
   HEAD LIGHT SW	Headlight control switch signal / ON or OFF	ON: Light control switch is in HEAD position OFF: Light control switch is not in HEAD position	-
   TAIL LIGHT SW	Taillight switch signal / ON or OFF	ON: Light control switch is in TAIL or HEAD position OFF: Light control switch is not in OFF position	-
   TURN LEFT SW	Turn signal switch LH signal / ON or OFF	ON: Light control switch is in LH position OFF: Light control switch is not in LH position	-
   TURN RIGHT SW	Turn signal switch RH signal / ON or OFF	ON: Light control switch is in RH position OFF: Light control switch is not in RH position	-
   TELESC SHORT SW	Telesc SHORT switch status / ON or OFF	ON: Telesc switch is in SHORT position OFF: Telesc switch is not in SHORT position	-
   TELESC LONG SW	Telesc LONG switch status / ON or OFF	ON: Telesc switch is in LONG position OFF: Telesc switch is not in LONG position	-
   TILT DOWN SW	Tilt DOWN switch / ON or OFF	ON: TILT switch is in DOWN position OFF: TILT switch is not in DOWN position	-
   TILT UP SW	Tilt UP switch / ON or OFF	ON: TILT switch is in UP position OFF: TILT switch is not in UP position	-
   IG SW SIG	Engine switch signal / ON or OFF	ON: Engine switch on (IG) OFF: Engine switch off	-

NG : Go to step 2 

OK : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

1. Remove the ECU-IG RH fuse from the cowl side junction block RH.
2. Remove the MPX-B fuse from the engine room No. 1 relay block.
3. Remove the D/C CUT fuse from the engine room No. 1 relay block.
4. Measure the resistance of the fuses.

   Standard resistance: Below 1 Ω 

NG : REPLACE FUSE 

OK : GO TO NEXT STEP 

1. Disconnect the K22 switch connector.
2. Measure the voltage and resistance of the wire harness side connector.

   Standard voltage 

   STANDARD VOLTAGE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   K22-2 (IG) - K22-5 (E)	Engine switch on (IG)	10 to 14 V
   K22-1 (B) - K22-5 (E)	Always	10 to 14 V

   Standard resistance 

   STANDARD RESISTANCE SPECIFICATION
   
   

   Tester Connection	Specified Condition
   K22-5 (E) - Body ground	Below 1 Ω

   Fig 2: Identifying K22 Switch Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

OK : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE