Toyota Yaris: Air Conditioning System / Front Left Air Mix Damper Control Servo Motor Actuator Stuck Off (B144C7F)

Toyota Yaris XP210 (2020-2024) Reapir and Service Manual / Vehicle Interior / Heating / Air Conditioning / Air Conditioning System / Front Left Air Mix Damper Control Servo Motor Actuator Stuck Off (B144C7F)

DESCRIPTION

The No. 1 air conditioning radiator damper servo sub-assembly sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the air outlet damper to the appropriate position, which controls the air outlet switching.

The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Memory
B144C7F	Front Left Air Mix Damper Control Servo Motor Actuator Stuck Off	Diagnosis Condition: No. 1 air conditioning radiator damper servo sub-assembly operating Malfunction Status: Damper servo operation request signals are output but the damper position sensor value does not change or abnormal Detection Time: Continuously for 30 seconds or more	No. 1 air conditioning radiator damper servo sub-assembly Air conditioning harness assembly Air conditioning radiator assembly	Memorized

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B144C7F

Front Left Air Mix Damper Control Servo Motor Actuator Stuck Off

Diagnosis Condition:

No. 1 air conditioning radiator damper servo sub-assembly operating

Malfunction Status:

Damper servo operation request signals are output but the damper position sensor value does not change or abnormal

Detection Time:

Continuously for 30 seconds or more

No. 1 air conditioning radiator damper servo sub-assembly
Air conditioning harness assembly
Air conditioning radiator assembly

Memorized

DTC Detection Condition Combination Table

		Vehicle Condition
		Pattern 1	Pattern 2
Diagnosis Condition	No. 1 air conditioning radiator damper servo sub-assembly operating	○	○
Malfunction	Damper servo operation request signals are output but the damper position sensor value does not change	○	-
Malfunction	Damper servo operation request signals are output but the damper position sensor value is abnormal	-	○
Detection Time		Continuously for 30 seconds or more	Continuously for 30 seconds or more
Trip Count		1 trip	1 trip

HINT:

If the conditions of either of these patterns are detected, a DTC will be stored

CAUTION / NOTICE / HINT

NOTICE:

This DTC is also output for the damper link, damper lock, etc. Before performing inspection, perform servomotor initialization and check that there are no mechanical malfunctions.
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This DTC is also output when servomotor initialization has failed. When servomotor initialization has failed, repair any malfunctions and perform servomotor initialization again.
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PROCEDURE

1.	CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION)

(a) Check that the No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

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OK:

The No. 1 air conditioning radiator damper servo sub-assembly is installed correctly.

INSTALL NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY CORRECTLY

2.	CHECK NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (MOTOR, LINK, DAMPER)

(a) Check for a wire harness caught between the links of the motors and dampers.

OK:

No wire harnesses are caught between the links of the motors and dampers.

REMOVE PINCHED WIRE HARNESS

3.	CHECK AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER)

(a) Remove the No. 1 air conditioning radiator damper servo sub-assembly.

Click here

(b) Operate the dampers by hand.

OK:

The dampers are easily operated by hand.

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY

REPLACE AIR CONDITIONING RADIATOR ASSEMBLY

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