Toyota Camry (XV70): Air Inlet Damper Control Servo Motor Circuit (B1442)

DESCRIPTION

The No. 1 blower 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 inlet damper to the appropriate position to change the air inlet mode (fresh, recirculation/fresh, and recirculation).

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
B1442	Air Inlet Damper Control Servo Motor Circuit	Air inlet damper position sensor value does not change even if air conditioning amplifier assembly operates No. 1 blower damper servo sub-assembly	No. 1 blower damper servo sub-assembly No. 1 air conditioning radiator damper servo sub-assembly Air conditioning harness assembly Air conditioning amplifier assembly Blower assembly	Memorized (30 sec. or more)*

• *: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

DTC Detection Condition Combination Table

		Vehicle Condition
		Pattern 1	Pattern 2
Diagnosis Condition	No. 1 blower damper servo sub-assembly operating	0	0
Malfunction	Air inlet damper servo operation request signals are output but the air inlet damper position sensor value does not change	0	-
	Air inlet damper servo operation request signals are output but the air inlet damper position sensor value is abnormal	-	0
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.

WIRING DIAGRAM

for Dual Type

for Single Type

CAUTION / NOTICE / HINT

HINT:

• Confirm that no mechanical problems are present because this DTC can be stored when either a damper link or damper is mechanically locked.
• When installing a damper servo motor, make sure to install it correctly.

  Click here

• After replacing a damper servo motor, make sure to perform Servo Motor Initialization.

  Click here

PROCEDURE

1.	CONFIRM MODEL

Result	Proceed to
for Dual Type	A
for Single Type	B

B

GO TO STEP 10

A

2.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result	Proceed to
Only DTC B1497 is output	A
DTC B1441, B1442, B1443 and B1446 are output	B
Only DTC B1442 is output	C

A

GO TO DTC B1497

B

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

C

3.	INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION)

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

OK:

The No. 1 blower damper servo sub-assembly is installed correctly.

NG

INSTALL NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY CORRECTLY

OK

4.	INSPECT NO. 1 BLOWER 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.

NG

REMOVE PINCHED WIRE HARNESS

OK

5.	INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

(a) Remove the No. 1 blower damper servo sub-assembly.

Click here

(b) Operate the air inlet dampers by hand.

OK:

The air inlet dampers are easily operated by hand.

NG

REPLACE BLOWER ASSEMBLY

OK

6.	INSPECT AIR CONDITIONING HARNESS ASSEMBLY

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
6 (STE2) - 3 (sigB)	Always	Below 1 ?
5 (STE1) - 2 (sigA)	Always	Below 1 ?
8 (M-) - 5 (M-)	Always	Below 1 ?
7 (M+) - 4 (M+)	Always	Below 1 ?
4 (GND) - 1 (GND)	Always	Below 1 ?
6 (STE2) or 3 (sigB) - Other terminals and Body ground	Always	10 k? or higher
5 (STE1) or 2 (sigA) - Other terminals and Body ground	Always	10 k? or higher
8 (M-) or 5 (M-) - Other terminals and Body ground	Always	10 k? or higher
7 (M+) or 4 (M+) - Other terminals and Body ground	Always	10 k? or higher

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

OK

7.	CONFIRM MODEL

Result	Proceed to
w/ Rear Center Register	A
w/o Rear Center Register	B

B

GO TO STEP 9

A

8.	PERFORM ACTIVE TEST USING TECHSTREAM

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

(b) Remove the No. 2 air conditioning radiator damper servo sub-assembly.

Click here

(c) Connect the No. 1 blower damper servo sub-assembly connector to the No. 2 air conditioning radiator damper servo sub-assembly.

(d) Connect the Techstream to the DLC3.

(e) Turn the ignition switch to ON.

(f) Turn the Techstream on.

(g) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(h) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Air Inlet Damper Targ Pulse	No. 1 blower damper servo sub-assembly pulse*	Min.: 128 Max.: 383	Operates between 220 to 256 pulses

• *: Though this Active Test is for the No. 1 blower damper servo sub-assembly, in this case it is used to check the operation of the No. 2 air conditioning radiator damper servo sub-assembly.

Body Electrical > Air Conditioner > Active Test

Tester Display
Air Inlet Damper Targ Pulse

OK:

The No. 2 air conditioning radiator damper servo sub-assembly operates.

OK

REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

NG

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

9.	PERFORM ACTIVE TEST USING TECHSTREAM

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

(b) Connect the No. 1 blower damper servo sub-assembly connector.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

(f) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(g) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Air Inlet Damper Targ Pulse	No. 1 blower damper servo sub-assembly pulse	Min.: 128 Max.: 383	Operates between 220 to 256 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display
Air Inlet Damper Targ Pulse

OK:

The No. 1 blower damper servo sub-assembly operates.

OK

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

NG

REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

10.	CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Air Conditioner > Trouble Codes

Result	Proceed to
Only DTC B1497 is output	A
DTC B1441, B1442 and B1443 are output	B
Only DTC B1442 is output	C

A

GO TO DTC B1497

B

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

C

11.	INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY (INSTALLATION CONDITION)

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

OK:

The No. 1 blower damper servo sub-assembly is installed correctly.

NG

INSTALL NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY CORRECTLY

OK

12.	INSPECT NO. 1 BLOWER 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.

NG

REMOVE PINCHED WIRE HARNESS

OK

13.	INSPECT NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

(a) Remove the No. 1 blower damper servo sub-assembly.

Click here

(b) Operate the air inlet dampers by hand.

OK:

The air inlet dampers are easily operated by hand.

NG

REPLACE BLOWER ASSEMBLY

OK

14.	INSPECT AIR CONDITIONING HARNESS ASSEMBLY

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

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
6 (STE2) - 3 (sigB)	Always	Below 1 ?
5 (STE1) - 2 (sigA)	Always	Below 1 ?
8 (M-) - 5 (M-)	Always	Below 1 ?
7 (M+) - 4 (M+)	Always	Below 1 ?
4 (GND) - 1 (GND)	Always	Below 1 ?
6 (STE2) or 3 (sigB) - Other terminals and Body ground	Always	10 k? or higher
5 (STE1) or 2 (sigA) - Other terminals and Body ground	Always	10 k? or higher
8 (M-) or 5 (M-) - Other terminals and Body ground	Always	10 k? or higher
7 (M+) or 4 (M+) - Other terminals and Body ground	Always	10 k? or higher

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

OK

15.	PERFORM ACTIVE TEST USING TECHSTREAM

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

(b) Connect the No. 1 blower damper servo sub-assembly connector.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

(f) Enter the following menus: Body Electrical / Air Conditioner / Active Test.

(g) Perform the Active Test according to the display on the Techstream.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Air Inlet Damper Targ Pulse	No. 1 blower damper servo sub-assembly pulse	Min.: 128 Max.: 383	Operates between 220 to 256 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display
Air Inlet Damper Targ Pulse

OK:

The No. 1 blower damper servo sub-assembly operates.

OK

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

NG

REPLACE NO. 1 BLOWER DAMPER SERVO SUB-ASSEMBLY

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