| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM1000000026Z3W |
| Model Year Start: 2023 | Model: Corolla | Prod Date Range: [09/2022 - ] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B142A88; Servo Motor LIN Communication Bus off; 2023 - 2025 MY Corolla Corolla HV [09/2022 - ] | ||
|
DTC |
B142A88 |
Servo Motor LIN Communication Bus off |
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 |
|---|---|---|---|---|
|
B142A88 |
Servo Motor LIN Communication Bus off |
Diagnosis Condition:
Malfunction:
Detection Time:
|
|
Memorized |
DTC Detection Condition Combination Table
|
Vehicle Condition |
|||
|---|---|---|---|
|
Pattern 1 |
Pattern 2 |
||
|
Diagnosis Condition |
Ignition switch ON |
○ |
○ |
|
Malfunction |
Error in communication line between air conditioning amplifier assembly and each servo motor |
○ |
- |
|
Open in communication line between air conditioning amplifier assembly and each servo motor |
- |
○ |
|
|
Detection Time |
Continuously for 10 seconds or more |
Continuously for 10 seconds or more |
|
|
Trip Count |
1 trip |
1 trip |
|
HINT:
If the conditions of either of these patterns are detected, a DTC will be stored.
WIRING DIAGRAM
PROCEDURE
|
1. |
PERFORM ACTIVE TEST USING GTS |
(a) Perform the Active Test according to the display on the GTS.
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
Measurement Item |
Control Range |
Diagnostic Note |
|---|---|---|---|
|
Air Inlet Damper Control Servo Motor |
This test activates the air inlet damper control servo motor. (No. 1 blower damper servo sub-assembly) |
128: Min 384: Max |
Operate with the ignition switch ON. |
|
Front Air Mix Damper Control Servo Motor |
This test activates the front air mix damper control servo motor. (No. 1 air conditioning radiator damper servo sub-assembly (air mix)) |
128: Min 384: Max |
Operate with the ignition switch ON. |
|
Front Air Outlet Damper Control Servo Motor |
This test activates the front air outlet damper control servo motor. (No. 1 air conditioning radiator damper servo sub-assembly (front mode)) |
128: Min 384: Max |
Operate with the ignition switch ON. |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Air Inlet Damper Control Servo Motor |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Front Air Mix Damper Control Servo Motor |
Body Electrical > Air Conditioner > Active Test
|
Tester Display |
|---|
|
Front Air Outlet Damper Control Servo Motor |
|
Result |
Proceed to |
|---|---|
|
All of the damper servo motors do not operate |
A |
|
Any of the damper servo motors does not operate |
B |
|
All of the damper servo motors operate |
C |
| B |
|
| C |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
![2023 MY Corolla Corolla Hatchback Corolla HV GR Corolla [09/2022 - 11/2022]; HEATING / AIR CONDITIONING: AIR CONDITIONING AMPLIFIER: REMOVAL](/t3Portal/stylegraphics/info.gif)
|
|
2. |
CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY |
NOTICE:
When inspecting the air conditioning amplifier assembly, be careful not to cause a short.
(a) Disconnect the m3 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 |
|---|---|---|
|
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) - m3-2 (BUSG) |
Ignition switch off |
11 to 14 V |
(d) Using an oscilloscope, check the waveform.
|
Item |
Content |
|---|---|
|
Tester Connection |
m3-3 (BUS) - m3-2 (BUSG) |
|
Tool Setting |
2 V/DIV., 20 μs/DIV. |
|
Condition |
Ignition switch ON |
OK:
The waveform displays properly.
| OK |
|
| NG |
|
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
|
|
|