Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000ZPD8
Model Year Start: 2017 Model: Sienna Prod Date Range: [08/2016 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM: B1497/97; BUS IC Communication Malfunction; 2017 - 2020 MY Sienna [08/2016 -        ]

DTC

B1497/97

BUS IC Communication Malfunction

DESCRIPTION

The air conditioning harness connects the air conditioning amplifier and each servo. The air conditioning amplifier supplies power and sends operation instructions to each servo through the air conditioning harness. Each servo sends the damper position information to the air conditioning amplifier.

DTC Code

DTC Detection Condition

Trouble Area

B1497/97

Communication line error or open
  • Air conditioning harness
  • Rear air conditioning harness
  • Air mix control servo motor (for driver side)
  • Air mix control servo motor (for front passenger side)
  • Air outlet control servo motor
  • Air inlet control servo motor
  • Rear air mix control servo motor
  • Rear air outlet control servo motor
  • Air conditioning amplifier
  • Harness or connector

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

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

(e) Check the operation by referring to the table below.

Air Conditioner

Tester Display

Test Part

Control Range

Diagnostic Note

Air Mix Servo Targ Pulse (D)

Air mix servo motor pulse (D side)

Min.: 128, Max.: 383

-

Air Mix Servo Targ Pulse (P)

Air mix servo motor pulse (P side)

Min.: 128, Max.: 383

-

Air Outlet Servo Pulse (D)

Air outlet servo motor pulse

Min.: 128, Max.: 383

-

Air Inlet Damper Targ Pulse

Air inlet damper target pulse

Min.: 128, Max.: 383

-

Rear Air Mix Servo Targ Pulse

Rear air mix servo target pulse

Min.: 128, Max.: 383

-

A/O Servo Pulse (Rr D)

Rear air outlet servo motor pulse

Min.: 128, Max.: 383

-

OK:

Arm of the servo motor selected in the Active Test moves smoothly

(f) According to the test, proceed to the next step.

Result

Result

Proceed to

One of the front servo motors is malfunctioning

A

All of the front servo motors are malfunctioning

B

One of the rear servo motors is malfunctioning

C

All of the rear servo motors are malfunctioning

D
B

GO TO STEP 7

C

GO TO STEP 8

D

GO TO STEP 11

A

2.

SYSTEM CHECK

(a) According to the test, proceed to the next step.

Result

Result

Proceed to

Only the air mix control servo motor (for driver side) is malfunctioning

A

Only the air mix control servo motor (for front passenger side) is malfunctioning

B

Only the air outlet control servo motor is malfunctioning

C

Only the air inlet control servo motor is malfunctioning

D
B

GO TO STEP 4

C

GO TO STEP 5

D

GO TO STEP 6

A

3.

REPLACE AIR MIX CONTROL SERVO MOTOR (FOR DRIVER SIDE)

(a) Replace the air mix control servo motor (for driver side) (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

GO TO STEP 7

4.

REPLACE AIR MIX CONTROL SERVO MOTOR (FOR FRONT PASSENGER SIDE)

(a) Replace the air mix control servo (for front passenger side) (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

GO TO STEP 7

5.

REPLACE AIR OUTLET CONTROL SERVO MOTOR

(a) Replace the air outlet control servo motor (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

GO TO STEP 7

6.

REPLACE AIR INLET CONTROL SERVO MOTOR

(a) Replace the air inlet control servo motor (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

7.

REPLACE AIR CONDITIONING HARNESS

(a) Replace the air conditioning harness (See page 2017 - 2020 MY Sienna [08/2016 -        ]; HEATING / AIR CONDITIONING: FRONT AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the air conditioning harness cannot be inspected while it is removed from the vehicle, replace the air conditioning harness with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

GO TO STEP 13

8.

SYSTEM CHECK

(a) According to the test, proceed to the next step.

Result

Result

Proceed to

Only the rear air mix control servo motor is malfunctioning

A

Only the rear air outlet control servo motor is malfunctioning

B
B

GO TO STEP 10

A

9.

REPLACE REAR AIR MIX CONTROL SERVO MOTOR

(a) Replace the rear air mix control servo motor (See page 2016 - 2020 MY Sienna [12/2015 -        ]; HEATING / AIR CONDITIONING: REAR AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

GO TO STEP 11

10.

REPLACE REAR AIR OUTLET CONTROL SERVO MOTOR

(a) Replace the rear air outlet control servo motor (See page 2016 - 2020 MY Sienna [12/2015 -        ]; HEATING / AIR CONDITIONING: REAR AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

11.

CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - AIR CONDITIONING AMPLIFIER)

(a) Disconnect the L23 rear air conditioning harness connector.

(b) Disconnect the D186 air conditioning amplifier connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D186-27 (RBBU) - L23-4 (RBBU)

Always

Below 1 Ω

D186-1 (RBUS) - L23-3 (RBUS)

Always

Below 1 Ω

D186-25 (RBUG) - L23-2 (RBUG)

Always

Below 1 Ω

D186-27 (RBBU) - Body ground

Always

10 KΩ or higher

D186-1 (RBUS) - Body ground

Always

10 KΩ or higher

D186-25 (RBUG) - Body ground

Always

10 KΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

12.

REPLACE REAR AIR CONDITIONING HARNESS

(a) Replace the rear air conditioning harness (See page 2016 - 2020 MY Sienna [12/2015 -        ]; HEATING / AIR CONDITIONING: REAR AIR CONDITIONING UNIT: DISASSEMBLY ).

HINT:

Since the rear air conditioning harness cannot be inspected while it is removed from the vehicle, replace the rear air conditioning harness with a new or a known good one and check that the condition returns to normal.

(b) Check for the DTC.

Result

Result

Proceed to

DTC B1497/97 is not output

A

DTC B1497/97 is output

B
A

END
B

13.

CHECK HARNESS AND CONNECTOR (POWER SOURCE)

(a) Disconnect the D75 and D186 air conditioner amplifier connectors.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

D75-21 (B) - Body ground

Always

11 to 14 V

D186-28 (+B2) - Body ground

Always

11 to 14 V
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR