Inspection Procedure

1. Remove the air conditioning with connectors still connected.
2. Measure the voltage of the wire harness side connectors.

   Standard voltage 

   TERMINALS VOLTAGE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   A7-2 (ST1) - A7-15 (SGST)	Power switch ON (IG) Fr. DEF switch ON	Below 0.3 V
   A7-2 (ST1) - A7-15 (SGST)	Power switch ON (IG) Rr. DEF switch ON	0.8 to 1.5 V
   A7-2 (ST1) - A7-15 (SGST)	Power switch ON (IG) Recirculation/Fresh switch ON	2.0 to 2.9 V
   A7-1 (ST2) - A7-15 (SGST)	Power switch ON (IG) AUTO switch ON	Below 0.3 V
   A7-1 (ST2) - A7-15 (SGST)	Power switch ON (IG) TEMP+ switch ON	0.8 to 1.5 V
   A7-1 (ST2) - A7-15 (SGST)	Power switch ON (IG) TEMP- switch ON	2.0 to 2.9 V

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

Fig 1: Identifying Air Conditioning Amplifier Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : GO TO NEXT STEP 

1. Remove the steering pad switch LH.
2. Measure the resistance of the connectors.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   A2 (AC2) - B5 (AC1)	Always	1,210 Ω
   A7 (EAC) - B6 (EAC)	Always	Below 1 Ω
   A3 (AC1) - B5 (AC1)	Always	Below 1 Ω
   A2 (AC2) - A7 (EAC)	AUTO switch ON	Below 1 Ω
   A2 (AC2) - A7 (EAC)	TEMP + switch ON	300 Ω
   A2 (AC2) - A7 (EAC)	TEMP - switch ON	1,210 Ω

NG : REPLACE STEERING PAD SWITCH LH 

Fig 2: Identifying Steering Pad Switch Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Remove the steering pad switch RH.
2. Measure the resistance of the connector.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   2 (AC1) -1 (EAC)	Fr. DEF switch ON	Below 1 Ω
   2 (AC1) -1 (EAC)	Rr. DEF switch ON	300 Ω
   2 (AC1) -1 (EAC)	Recirculation/Fresh switch ON	1,210 Ω

NG : REPLACE STEERING PAD SWITCH RH 

Fig 3: Identifying Steering Pad Switch Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Connect the steering pad switch RH and LH to the steering pad switch cable.
2. Measure the resistance of the connector.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Condition	Specified Condition
   3 (AC1) - 7 (EAC)	Fr. DEF switch ON	Below 1 Ω
   3 (AC1) - 7 (EAC)	Rr. DEF switch ON	300 Ω
   3 (AC1) - 7 (EAC)	Recirculation/Fresh switch ON	1,210 Ω

NG : REPLACE STEERING PAD SWITCH ASSEMBLY 

Fig 4: Identifying Steering Pad Switch Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Remove the spiral cable.
2. Measure the resistance of the connectors.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Specified Condition
   C12-3 (EAC) - 7 (EAC)	Below 1 Ω
   C12-9 (AC2) - 2 (AC2)	Below 1 Ω
   C12-10 (AC1) - 3 (AC1)	Below 1 Ω

NG : REPLACE SPIRAL CABLE SUB-ASSEMBLY 

Fig 5: Identifying Steering Pad Switch Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : GO TO NEXT STEP 

1. Disconnect the C12 steering pad connector.
2. Disconnect the A7 amplifier connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TERMINALS RESISTANCE SPECIFICATIONS
   
   

   Tester Connection	Specified Condition
   A7-2 (ST1) - C12-10 (AC1)	Below 1 Ω
   A7-15 (SGST) - C12-3 (EAC)	Below 1 Ω
   A7-1 (ST2) - C12-9 (AC2)	Below 1 Ω
   A7-2 (ST1) - Body ground	10 kΩ or higher
   A7-15 (SGST) - Body ground	10 kΩ or higher
   A7-1 (ST2) - Body ground	10 kΩ or higher

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 6: Disconnecting A7 Amplifier Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE AIR CONDITIONING AMPLIFIER