Last Modified: 07-31-2024 6.11:8.1.0 Doc ID: RM1000000025R3H
Model Year Start: 2023 Model: GR Corolla Prod Date Range: [09/2022 - 11/2022]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (except TMC Made, and Gasoline Model, with Manual Air Conditioning System for Electrical Control Type): B1497; Communication Malfunction (Bus Ic); 2023 MY Corolla Corolla Hatchback GR Corolla [09/2022 - 11/2022]

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
  • Air conditioning amplifier assembly

Memorized

(10 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.

WIRING DIAGRAM

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) 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 Outlet Servo Pulse (D)

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

Min.: 128

Max.: 383

Operates between 256 and 348 pulses

Body Electrical > Air Conditioner > Active Test

Tester Display

Air Outlet Servo Pulse (D)

OK:

The damper servo motor operates smoothly.

NG

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

OK

2.

INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

*a

Component without harness connected

(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 m3 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

m3-2 (BUSG) - 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

m3-4 (BUSB) - Body ground

Ignition switch ON

11 to 14 V

(d) Turn the ignition switch to ON.

(e) Using an oscilloscope, check the waveform.

Item

Content

Terminal No.

m3-3 (BUS) - m3-2 (BUSG)

Tool Setting

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

Condition

Ignition switch ON

OK:

Waveform is similar to that shown in the illustration.

HINT:

The waveform varies with the blower speed.

OK

REPLACE AIR CONDITIONING HARNESS ASSEMBLY

NG

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY