Toyota Yaris: Air Conditioning System / Operation not Accepted Even If Air Conditioning Switch is Operated

Toyota Yaris XP210 (2020-2024) Reapir and Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System / Operation not Accepted Even If Air Conditioning Switch is Operated

DESCRIPTION

If the air conditioning system cannot be operated using the air conditioning control assembly, the following factors may be the cause.

Symptom	Factor
Air conditioning system cannot be operated using air conditioning control assembly (With the exception of the switch indicators, no inputs are reflected when other switches operated)	LIN communication malfunction between air conditioning amplifier assembly and air conditioning control assembly Short to +B or ground in air conditioning amplifier assembly circuit Air conditioning amplifier assembly malfunction Air conditioning control assembly malfunction Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK FOR DTC

(a) Clear the DTCs.

Body Electrical > Air Conditioner > Clear DTCs

(b) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result	Proceed to
B14B287 is not output	A
B14B287 is output	B

GO TO DTC B14B287

2.	CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - POWER SOURCE AND BODY GROUND)

(a) Disconnect the air conditioning amplifier assembly connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
H24-5 (B) - Body ground	Always	11 to 14 V
H24-6 (IG+) - Body ground	Ignition switch ON	11 to 14 V
H24-6 (IG+) - Body ground	Ignition switch off	Below 1 V

Standard Resistance:

Tester Connection	Condition	Specified Condition
H24-17 (GND) - Body ground	Always	Below 1 Ω

*a	Front view of wire harness connector (to Air Conditioning Amplifier Assembly)

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

REPAIR OR REPLACE HARNESS OR CONNECTOR

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