AIR CONDITIONING SYSTEM, Diagnostic DTC:B1487

DTC Code	DTC Name
B1487	Air Outlet Damper Control Servo Motor Circuit(Passenger Side Front A/C Rear Air Flow)

DESCRIPTION

*1: for LHD
*2: for RHD

The heater air damper assembly (MODE FACE (rear RH))*1 or heater air damper assembly (MODE FACE (rear LH))*2 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 heater air damper assembly (MODE FACE (rear RH))*1 or heater air damper assembly (MODE FACE (rear LH))*2 to the appropriate position. This adjusts the amount of air passing through the heater core after passing the evaporator and controls the temperature of the output air. 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
B1487	Air Outlet Damper Control Servo Motor Circuit(Passenger Side Front A/C Rear Air Flow)	Diagnosis condition: During heater air damper assembly (MODE FACE (rear RH))1 or heater air damper assembly (MODE FACE (rear LH))2 operation Malfunction status: The damper servo operation request signal is output but the position information of the servo does not change or servo is malfunctioning Detection time: Continuously for 30 seconds or more	Heater air damper assembly (MODE FACE (rear RH)1 Heater air damper assembly (MODE FACE (rear LH)2 Air conditioning harness assembly Air conditioning amplifier assembly	Memorized

DTC Detection Condition Combination Table
		Vehicle Condition
		Pattern 1	Pattern 2
Diagnosis Condition	During heater air damper assembly (MODE FACE (rear RH) operation	○	○
Malfunction Status	The damper servo operation request signal is output but the position information of the servo does not change	○	-
Malfunction Status	The damper servo operation request signal is output but the position information of the servo is malfunctioning	-	○
Detection Time		Continuously for 30 seconds or more	Continuously for 30 seconds or more
Trip Count		1 trip	1 trip

Tech Tips

If the conditions match either of these patterns, a DTC will be output.

WIRING DIAGRAM

Figure 1. for LHD:

Figure 2. for RHD:

CAUTION / NOTICE / HINT

Note

Confirm that no mechanical problem is present because this diagnostic code can be output when either a damper link or the damper is mechanically locked.
When installing the damper servo motor, make sure to install it correctly.
When the servo motor is replaced, be sure to perform servo motor initialization.

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Tech Tips

Confirm that no mechanical problem is present because this DTC can be output when either a damper link or damper is mechanically locked.

PROCEDURE

CHECK FOR DTC

Check for DTCs.

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Body Electrical > Air Conditioner > Trouble Codes

Result

Result	Proceed to
DTC B1487 is output	A
DTC B1487 and B1497 are output.	B

GO TO DTC B1497 Click here

CHECK HEATER AIR DAMPER ASSEMBLY

Check for heater air damper assembly is installed correctly.

OK
Heater air damper servo assembly is installed correctly.

Result

Proceed to
OK
NG

REINSTALL HEATER AIR DAMPER ASSEMBLY Click here

CHECK HEATER AIR DAMPER ASSEMBLY (MOTOR, LINK, DAMPER)

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

REMOVE PINCHED WIRE HARNESS

CHECK AIR CONDITIONING RADIATOR ASSEMBLY (DAMPER)

Remove the heater air damper assembly.

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Operate the dampers by hand.

OK
The dampers are easily operated by hand.

Result

Proceed to
OK
NG

REPAIR OR REPLACE AIR CONDITIONING RADIATOR ASSEMBLY

PERFORM ACTIVE TEST USING GTS (A/O SERVO PULSE (F&R P))

*1: for LHD
*2: for RHD
*3: Actually operates the heater air damper assembly (MODE FACE (rear RH))*1 or heater air damper assembly (MODE FACE (rear LH))*2.

Remove the heater air damper assembly.

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Connect the heater air damper assembly (MODE FACE (rear RH))*1 or heater air damper assembly (MODE FACE (rear LH))*2 connector to heater air damper assembly (MODE FACE (rear LH)).
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Body Electrical / Air Conditioner / Active Test.

Check the operation by referring to the table below.

Body Electrical > Air Conditioner > Active Test

Tester Display	Measurement Item	Control Range	Restrict Condition
A/O Servo Pulse(F&R D)	for LHD: Heater air damper servo assembly (MODE FACE (rear LH)) operation3 for RHD:* Heater air damper servo assembly (MODE FACE (rear RH)) operation*3	Min.: 128 Max.: 383	for LHD: Operates between 234 and 263 pulses for RHD: Operates between 249 and 278 pulses

Tester Display

Measurement Item

Control Range

Restrict Condition

A/O Servo Pulse(F&R D)

for LHD:

Heater air damper servo assembly (MODE FACE (rear LH)) operation*3

for RHD:

Heater air damper servo assembly (MODE FACE (rear RH)) operation*3

Min.: 128

Max.: 383

for LHD:

Operates between 234 and 263 pulses

for RHD:

Operates between 249 and 278 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display
A/O Servo Pulse(F&R D)

OK
Heater air damper assembly (FACE MODE (rear RH))1 or heater air damper assembly (FACE MODE (rear LH))2 is operated.

Result

Proceed to
OK
NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

CHECK HEATER AIR DAMPER ASSEMBLY

Interchange the MODE FACE (rear RH) servo motor with MODE FACE (rear LH) servo motor and connect the connectors to them.

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Clear the DTCs.

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Check for DTCs.

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Result

Result	Proceed to
DTC B1486 is output	A
DTC B1487 is output	B
DTCs are not output	C

Tech Tips

Codes other than DTC B1486 and B1487 may be output at this time, but they are not related to this check.

REPLACE HEATER AIR DAMPER ASSEMBLY Click here

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

USE SIMULATION METHOD TO CHECK Click here