Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001FPEE
Model Year Start: 2019 Model: RAV4 Prod Date Range: [11/2018 - 08/2020]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B1497; Communication Malfunction (Bus Ic); 2019 - 2020 MY RAV4 [11/2018 - 08/2020]

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)
  • Diagnosis condition: None
  • Malfunction status: Error or open in communication line between air conditioning amplifier assembly and servo motor
  • Air conditioning harness assembly
  • No. 1 air conditioning radiator damper servo sub-assembly
  • No. 2 air conditioning radiator damper servo sub-assembly
  • No. 3 air conditioning radiator damper servo sub-assembly (w/ Driver Seat Centralized Control)
  • No. 1 blower damper servo sub-assembly
  • Air conditioning amplifier assembly

Memorized

WIRING DIAGRAM

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (SERVO PULSE)

(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.

Body Electrical > Air Conditioner > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Air Mix Servo Targ Pulse(D)

for Automatic Air Conditioning System:

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

for Manual Air Conditioning System:

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

Min.: 128

Max.: 383

Operates between 165 to 257 pulses

Air Mix Servo Targ Pulse(P)

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

Min.: 128

Max.: 383

Operates between 255 to 347 pulses

(for Automatic Air Conditioning System)

Air Outlet Servo Pulse (D)

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

Min.: 128

Max.: 383

w/ Driver Seat Centralized Control

  • Operates between 164 to 278 pulses

w/ Front Seat Centralized Control

  • Operates between 234 to 348 pulses

Air Inlet Damper Targ Pulse

No. 1 blower damper servo sub-assembly pulse

Min.: 128

Max.: 383

Operates between 220 to 256 pulses

Air Outlet Servo Pulse (P)

No. 3 air conditioning radiator damper servo sub-assembly (front passenger side mode) pulse

Min.: 128

Max.: 383

Operates between 234 to 348 pulses

(w/ Driver Seat Centralized Control)

A/O Servo Pulse(Rr D)

No. 2 air conditioning radiator damper servo sub-assembly (rear mode) 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

Air Mix Servo Targ Pulse(P)

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Outlet Servo Pulse (D)

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Inlet Damper Targ Pulse

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Outlet Servo Pulse (P)

Body Electrical > Air Conditioner > Active Test

Tester Display

A/O Servo Pulse(Rr D)

OK:

Damper servo motor is operated.

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

Result

Proceed to

All damper servo motors are not operated

A

Any damper servo motor is not operated

B

All damper servo motors are operated

C
B

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

C

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

A

2.

CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (POWER SOURCE CIRCUIT)

(a) Disconnect the air conditioning amplifier assembly connector.

*a

Component without harness connected

(Air Conditioning Amplifier Assembly)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

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

2 (BUS G) - 4 (B BUS)

Always

11 to 14 V

(d) Using an oscilloscope, check the waveform.

Item

Content

Tester Connection

2 (BUS G) - 3 (BUS)

Tool Setting

2 V/DIV., 20 μs/DIV.

Condition

Ignition switch ON

OK:

The waveform displays properly.

OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPLACE AIR CONDITIONING HARNESS ASSEMBLY