Pattern Select Switch Eco Mode Circuit [10/2018 - 07/2022]: Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE USING TECHSTREAM (CAN BUS CHECK)

See step 2

Result

Result	Proceed to
All of the ECUs and sensors that are currently connected to the CAN communication system are displayed.	A
None of the ECUs and sensors that are currently connected to the CAN communication system are displayed, or some of them are not displayed.	B

Result:

GO TO CAN COMMUNICATION SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ]

Result:

See step 2

CHECK DTC OUTPUT (HEALTH CHECK)

See step 3

Result

Result	Proceed to
No DTCs are output.	A
DTCs are output.	B

Result:

GO TO DTC CHART Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2018 - ]

Result:

See step 3

READ VALUE USING TECHSTREAM (ECO SWITCH)

Connect Techstream the to the DLC3.
Turn the power switch on (IG).

Enter the following menus: Body Electrical / Air Conditioning / Data List / ECO Switch.

Body Electrical > Air Conditioner > Data List

Tester Display
ECO Switch

Read the value displayed on the Techstream.

Body Electrical > Air Conditioner > Data List

Tester Display	Measurement Item	Range	Normal Condition
ECO Switch	ECO mode switch condition	ON or OFF	Drive mode select switch (combination switch assembly)being pushed and held: ON Drive mode select switch (combination switch assembly)not operated: OFF

Result

Result	Proceed to
The Techstream display changes according to the ECO mode switch operation.	A
The Techstream display does not change according to the ECO mode switch operation.	B

Result:

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to REMOVAL [10/2018 - 07/2022]

Result:

See step 4

INSPECT DRIVE MODE SELECT SWITCH (COMBINATION SWITCH ASSEMBLY) (ECO MODE)
Refer to INSPECTION [10/2018 - ]

Result

Proceed to

OK

NG

Result:

NG

REPLACE DRIVE MODE SELECT SWITCH (COMBINATION SWITCH ASSEMBLY). Refer to REMOVAL [10/2018 - 07/2022]

Result:

OK

See step 5

CHECK HARNESS AND CONNECTOR (DRIVE MODE SELECT SWITCH (COMBINATION SWITCH ASSEMBLY) - BODY GROUND)

Disconnect the I1 drive mode select switch (combination switch assembly) connector.

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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Front view of wire harness connector (to Drive Mode Select Switch (Combination Switch Assembly))

Standard Resistance

Tester Connection	Condition	Specified Condition
I1-7 (GND) - Body ground	Always	Below 1 Ω

Reconnect the I1 drive mode select switch (combination switch assembly) connector.

Result

Proceed to
OK
NG

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

Result:

See step 6

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - DRIVE MODE SELECT SWITCH (COMBINATION SWITCH ASSEMBLY))

Disconnect the F50 air conditioning amplifier assembly connector.
Disconnect the I1 drive mode select switch (combination switch assembly) connector.

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

*a	Front view of wire harness connector (to Air Conditioning Amplifier Assembly)
*b	Front view of wire harness connector (to Drive Mode Select Switch (Combination Switch Assembly))

Standard Resistance

Tester Connection	Condition	Specified Condition
F50-20 (ECOS) - I1-6 (ECU)	Always	Below 1 Ω
F50-20 (ECOS) or I1-6 (ECU) - Body ground	Always	10 kΩ or higher

Reconnect the I1 drive mode select switch (combination switch assembly) connector.

Reconnect the F50 air conditioning amplifier assembly connector.

Result

Proceed to
OK
NG

Result:

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to REMOVAL [10/2018 - 07/2022]

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR