Air Conditioning System Steering Pad Switch Circuit

Heater & Air Conditioning System. Camry. Acv40 Gsv40
Air Conditioning. Camry. Acv40 Gsv40

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT A/C CONTROL ASSEMBLY

INSPECT STEERING PAD SWITCH ASSEMBLY

INSPECT SPIRAL CABLE SUB-ASSEMBLY

CHECK HARNESS AND CONNECTOR (A/C CONTROL ASSEMBLY - SPIRAL CABLE SUB-ASSEMBLY)

AIR CONDITIONING SYSTEM - Steering Pad Switch Circuit


DESCRIPTION

AUTO, OFF, TEMP UP (+), and TEMP DOWN (-) switches are located on the steering pad switch. The resistance of the steering pad switch changes in accordance with switch operation. The A/C control assembly (heater control base sub-assembly) outputs voltage to the steering pad switch and reads voltage changes due to the resistance changes that result from switch operation.
HINT:
If there is an open in the circuit, the A/C system cannot be operated by the steering pad switch assembly.
If there is a short in the circuit, the resulting condition is the same as if the switch were continuously depressed. Therefore, the A/C control assembly (heater control base sub-assembly) cannot be operated by the steering pad switch assembly, and the A/C control assembly (heater control base sub-assembly) will not be able to function correctly.

WIRING DIAGRAM


Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit


INSPECTION PROCEDURE

1.INSPECT A/C CONTROL ASSEMBLY


    Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit

  1. Remove the A/C control assembly (heater control base sub-assembly) with the connectors still connected.

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection (Symbols)
    		Condition
    		Specified Condition
    F16-9 (ADI1) - F16-8 (SG)
    		AUTO switch: ON
    		Below 2.5 Ω
    F16-9 (ADI1) - F16-8 (SG)
    		OFF switch: ON
    		Approx. 329 Ω
    F16-9 (ADI1) - F16-8 (SG)
    		TEMP+ switch: ON
    		Approx. 1,000 Ω
    F16-9 (ADI1) - F16-8 (SG)
    		TEMP- switch: ON
    		Approx. 3,110 Ω


NG
Go to step 2
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2.INSPECT STEERING PAD SWITCH ASSEMBLY

  1. Remove the steering pad switch assembly.



  1. Disconnect the connector from the steering pad switch assembly.


    Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:

    Tester Connection (Symbols)
    		Condition
    		Specified Condition
    a1-3 (AC1) - a1-2 (EAC)
    		AUTO switch: ON
    		Below 2.5 Ω
    a1-3 (AC1) - a1-2 (EAC)
    		OFF switch: ON
    		Approx. 329 Ω
    a1-3 (AC1) - a1-2 (EAC)
    		TEMP+ switch: ON
    		Approx. 1,000 Ω
    a1-3 (AC1) - a1-2 (EAC)
    		TEMP- switch: ON
    		Approx. 3,110 Ω


NG
REPLACE STEERING PAD SWITCH ASSEMBLY
OK


3.INSPECT SPIRAL CABLE SUB-ASSEMBLY


    Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit

  1. Disconnect the connector from the spiral cable sub-assembly.

  1. Measure the resistance according to the value(s) in the table below.

Standard resistance:
Tester Connection (Symbols)
Condition
Specified Condition
E18-10 (AC1) - a1-3 (AC1)
Center
Below 1 Ω
2.5 rotations to the left
2.5 rotations to the right
E18-9 (EAC) - a1-2 (EAC)
Center
Below 1 Ω
2.5 rotations to the left
2.5 rotations to the right
HINT:
The spiral cable makes a maximum of approximately 5 rotations.


NG
REPLACE SPIRAL CABLE SUB-ASSEMBLY
OK


4.CHECK HARNESS AND CONNECTOR (A/C CONTROL ASSEMBLY - SPIRAL CABLE SUB-ASSEMBLY)


    Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit

  1. Disconnect the connector from the A/C control assembly (heater control base sub-assembly).



    Camry. Acv40 Gsv40.Air Conditioning.Air Conditioning System.Air Conditioning System Steering Pad Switch Circuit

  1. Disconnect the connector from the spiral cable sub-assembly.

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection
    		Condition
    		Specified Condition
    F16-9 (ADI1) - E18-10 (AC1)
    		Always
    		Below 1 Ω
    F16-8 (SG) - E18-9 (EAC)
    		Always
    		Below 1 Ω
    F16-9 (ADI1) - E18-10 (AC1)
    		Always
    		10 kΩ or higher
    F16-8 (SG) - E18-9 (EAC)
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE HEATER CONTROL BASE SUB-ASSEMBLY