| Last Modified: 06-05-2026 | 6.11:8.1.0 | Doc ID: RM1000000025R2C |
| 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 Automatic Air Conditioning System): B1497; Communication Malfunction (Bus Ic); 2023 MY GR Corolla Corolla Corolla Hatchback [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 |
|
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 engine switch on (IG).
(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
OK:
The damper servo motor operates smoothly.
| NG |
|
REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY |
|
|
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 |
Engine switch on (IG) |
11 to 14 V |
(d) Turn the engine switch on (IG).
(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 |
Engine switch on (IG) |
OK:
Waveform is similar to that shown in the illustration.
HINT:
The waveform varies with the blower speed.
|
|
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