ECO Switch Circuit

AIR CONDITIONING: AIR CONDITIONING SYSTEM: ECO Switch Circuit

ECO Switch Circuit

DESCRIPTION

The ECO switch is installed on the instrument panel on the driver's seat side. When the ECO switch is turned on, the A/C amplifier receives an ECO switch ON signal and controls the air conditioning to enhance fuel efficiency.
When the heater is on, the engine ON request coolant temperature will be set to a lower level. Thus, the length of time that the engine operates to generate the heat necessary to operate the heater will be limited. When the engine coolant temperature drops, the amount of air flow of the blower motor will also decrease. If FOOT/DEF or DEF is selected, or if the temperature is set to MAX HOT, the fuel efficiency control due to the ECO switch operation will be canceled.
When the air conditioning is used to cool the vehicle, the power consumption of the compressor will be limited. Initially, the air conditioning will operate normally until the cabin temperature stabilizes. After the cabin temperature stabilizes, the power consumption of the compressor will be limited while stabilizing the cabin temperature. If the temperature is set to MAX COOL, the fuel efficiency control due to the ECO switch operation will be canceled.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT AIR CONDITIONING AMPLIFIER




(a) Remove the A/C amplifier with the connectors still connected.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- CHECK HARNESS AND CONNECTOR (ECO SWITCH - BATTERY)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. CHECK HARNESS AND CONNECTOR (ECO SWITCH - BATTERY)




(a) Disconnect the connector from the ECO switch.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. INSPECT ECO SWITCH




(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(b) Connect the positive (+) lead from the battery to terminal 2 (IND+), and the negative (-) lead to terminal 7 (IND-).
Check that the indicator light comes on.
OK:
Indicator light comes on.
NG -- REPLACE ECO SWITCH
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (ECO SWITCH - A/C AMPLIFIER)




(a) Disconnect the connector from the A/C amplifier.




(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER