Last Modified: 11-20-2023 6.11:8.1.0 Doc ID: RM100000001E5ZN
Model Year Start: 2019 Model: Camry Prod Date Range: [08/2018 - 08/2021]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System): B1497; Communication Malfunction (Bus Ic); 2019 - 2021 MY Camry [08/2018 - 08/2021]

DTC

B1497

Communication Malfunction (Bus Ic)

DESCRIPTION

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

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1497

Communication Malfunction (Bus Ic)

Error or open in communication line

  • Air conditioning harness assembly
  • No. 1 air conditioning radiator damper servo sub-assembly
  • No. 2 air conditioning radiator damper servo sub-assembly*1
  • Air conditioning amplifier assembly

Memorized

(10 sec. or more)*2

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

WIRING DIAGRAM

for Dual Type

for Single Type

PROCEDURE

1.

CONFIRM MODEL

Result

Proceed to

for Dual Type

A

for Single Type

B

B

GO TO STEP 7

A

2.

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) 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 Mix Servo Targ Pulse(D)

No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) pulse

Min.: 128

Max.: 383

Operates between 165 to 257 pulses

A/O Servo Pulse(Rr D)

No. 2 air conditioning radiator damper servo sub-assembly pulse

Min.: 128

Max.: 383

Operates between 158 to 260 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(D)

Body Electrical > Air Conditioner > Active Test

Tester Display

A/O Servo Pulse(Rr D)

Result

Proceed to

All of the damper servo motors are malfunctioning

A

One of the damper servo motors is malfunctioning

B

B

GO TO STEP 5

A

3.

PERFORM ACTIVE TEST USING TECHSTREAM

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / Air Conditioner / Active test.

(f) 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

A/O Servo Pulse(Rr D)

No. 2 air conditioning radiator damper servo sub-assembly pulse

Min.: 128

Max.: 383

Operates between 158 to 260 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

A/O Servo Pulse(Rr D)

OK:

The damper servo motor operates smoothly.

OK

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

4.

INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

NOTICE:

When inspecting the air conditioning amplifier assembly, do not bring the tester probes too close to each other as a short circuit may occur.

(a) Disconnect the z28 air conditioning amplifier assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

z28-2 (BUS G) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

z28-4 (B BUS) - Body ground

Ignition switch ON

11 to 14 V

(d) Turn the ignition switch to ON.

*a

Component with harness connected

(Air Conditioning Amplifier Assembly)

(e) Connect an oscilloscope to terminals z28-2 (BUS G) and z28-3 (BUS) of the air conditioning amplifier assembly and check the waveform.

OK:

Waveform is similar to that shown in the illustration.

HINT:

The waveform varies with the blower speed.

Item

Content

Tool Setting

2 V/DIV., 2 ms./DIV.

Condition

Ignition switch ON

OK

REPLACE AIR CONDITIONING HARNESS ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

5.

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) 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 Mix Servo Targ Pulse(D)

No. 1 air conditioning radiator damper servo sub-assembly (driver side air mix) pulse

Min.: 128

Max.: 383

Operates between 165 to 257 pulses

A/O Servo Pulse(Rr D)

No. 2 air conditioning radiator damper servo sub-assembly pulse

Min.: 128

Max.: 383

Operates between 158 to 260 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(D)

Body Electrical > Air Conditioner > Active Test

Tester Display

A/O Servo Pulse(Rr D)

Result

Proceed to

Only the No. 1 air conditioning radiator damper servo sub-assembly does not operate

A

Only the No. 2 air conditioning radiator damper servo sub-assembly does not operate

B

B

REPLACE AIR CONDITIONING HARNESS ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

A

6.

INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY)

(a) Disconnect the z28 air conditioning amplifier assembly connector.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

z28-2 (BUS G) - A-3 (GND)

Always

Below 1 Ω

z28-3 (BUS) - A-2 (LIN)

Always

Below 1 Ω

z28-4 (B BUS) - A-1 (+B)

Always

Below 1 Ω

OK

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

7.

PERFORM ACTIVE TEST USING TECHSTREAM

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

(b) Connect the Techstream to the DLC3.

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / Air Conditioner / Active test.

(f) 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 Mix Servo Targ Pulse(D)

No. 1 air conditioning radiator damper servo sub-assembly (air mix) pulse

Min.: 128

Max.: 383

Operates between 165 to 257 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Mix Servo Targ Pulse(D)

OK:

The damper servo motor operates smoothly.

OK

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

8.

INSPECT AIR CONDITIONING HARNESS ASSEMBLY (AIR CONDITIONING AMPLIFIER ASSEMBLY - NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY)

(a) Disconnect the z29 air conditioning amplifier assembly connector.

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

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

z29-2 (1A) - B-3 (GND)

Always

Below 1 Ω

z29-3 (2A) - B-2 (LIN)

Always

Below 1 Ω

z29-4 (3A) - B-1 (+B)

Always

Below 1 Ω

OK

REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY 2018 - 2020 MY Camry [03/2017 - 10/2020]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY 2021 - 2024 MY Camry [10/2020 -        ]; HEATING / AIR CONDITIONING: AIR CONDITIONING UNIT: DISASSEMBLY