DTC B143B-7F: Air Inlet Damper Control Servo Motor Actuator Stuck Off [11/2021 - ]: Procedure

1. Check for DTCs.

   Body Electrical > Air Conditioner > Trouble Codes 

   Result

   Result	Proceed to
   DTC B1403-7F, B143B-7F, B144C-7F and B145B-7F are output	A
   DTC B143B-7F is output	B

Result: 

A 

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [11/2021 - 03/2024]  , or refer to  DISASSEMBLY [03/2024 - ] 

Result: 

B 

See step  2

1. Perform the Active Test according to the display on the GTS.

   Body Electrical > Air Conditioner > Active Test 

   Tester Display	Measurement Item	Control Range	Diagnostic Note
   Air Inlet Damper Control Servo Motor	This test activates the Air Inlet Damper Control Servo Motor. (No. 3 air conditioning radiator damper servo sub-assembly)	128: Min 384: Max	Operate with ignition switch ON.

   Body Electrical > Air Conditioner > Active Test 

   Tester Display
   Air Inlet Damper Control Servo Motor

   OK

   No. 3 air conditioning radiator damper servo sub-assembly is operated.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [11/2021 - 03/2024]  , or refer to  DISASSEMBLY [03/2024 - ] 

Result: 

OK 

See step  3

1. Check that the No. 3 air conditioning radiator damper servo sub-assembly is installed correctly.

   Refer to REASSEMBLY [11/2021 - ]

   OK

   No. 3 air conditioning radiator damper servo sub-assembly is installed correctly.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REINSTALL NO. 3 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  REASSEMBLY [11/2021 - ] 

Result: 

OK 

See step  4

1. 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.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REMOVE PINCHED WIRE HARNESS 

Result: 

OK 

See step  5

1. Remove the No. 3 air conditioning radiator damper servo sub-assembly.

   Refer to DISASSEMBLY [11/2021 - ]

2. Operate the dampers by hand.

   OK

   The dampers are easily operated by hand.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE BLOWER ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

Result: 

OK 

See step  6

1. Disconnect the A No. 1 air conditioning radiator damper servo sub-assembly connector.
2. Disconnect the B No. 3 air conditioning radiator damper servo sub-assembly connector.
3. 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 No. 1 Air Conditioning Radiator Damper Servo Sub-assembly)

   *b

   Front view of wire harness connector (to No. 3 Air Conditioning Radiator Damper Servo Sub-assembly)

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A-1 (M-) - B-5 (M-)	Always	Below 1 Ω
   A-2 (M+) - B-4 (M+)	Always	Below 1 Ω
   A-3 (STE2) - B-3 (STE2)	Always	Below 1 Ω
   A-4 (STE1) - B-2 (STE1)	Always	Below 1 Ω
   A-5 (GND) - B-1 (GND)	Always	Below 1 Ω
   A-1 (M-) or B-5 (M-) - Other terminals and body ground	Always	10 kΩ or higher
   A-2 (M+) or B-4 (M+) - Other terminals and body ground	Always	10 kΩ or higher
   A-3 (STE2) or B-3 (STE2) - Other terminals and body ground	Always	10 kΩ or higher
   A-4 (STE1) or B-2 (STE1) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE NO. 3 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY. Refer to  DISASSEMBLY [11/2021 - ] 

Result: 

NG 

REPAIR AIR CONDITIONING HARNESS ASSEMBLY. Refer to  DISASSEMBLY [11/2021 - 03/2024]  , or refer to  DISASSEMBLY [03/2024 - ]