| Last Modified: 07-31-2024 | 6.11:8.1.0 | Doc ID: RM100000001H97M |
| Model Year Start: 2020 | Model: Corolla | Prod Date Range: [01/2019 - 09/2022] |
| Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for HV Model): B14B2; Lost Communication with Front Panel LIN; 2020 - 2022 MY Corolla Corolla HV [01/2019 - 09/2022] | ||
|
DTC |
B14B2 |
Lost Communication with Front Panel LIN |
DESCRIPTION
The air conditioning control assembly communicates with the air conditioning amplifier assembly via LIN communication.
If a malfunction occurs in the LIN communication system, the air conditioning amplifier assembly will not operate, even if the air conditioning control assembly is operated.
|
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
Memory |
|---|---|---|---|---|
|
B14B2 |
Lost Communication with Front Panel LIN |
Lost communication with air conditioning control 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
CAUTION / NOTICE / HINT
NOTICE:
Inspect the fuses for circuits related to this system before performing the following procedure.
PROCEDURE
|
1. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - IG POWER SOURCE AND BODY GROUND) |
(a) Disconnect the I37 air conditioning control assembly connector.
(b) Measure the voltage and resistance according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I37-9 (IG+) - Body ground |
Power switch on (IG) |
11 to 14 V |
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I37-13 (GND) - Body ground |
Always |
Below 1 Ω |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
2. |
CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the I49 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 |
|---|---|---|
|
I37-7 (LIN1) - I49-7 (LIN1) |
Always |
Below 1 Ω |
|
I37-7 (LIN1) or I49-7 (LIN1) - Other terminals and body ground |
Always |
10 kΩ or higher |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
3. |
INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY |
(a) Connect the I49 air conditioning amplifier assembly connector.
(b) Turn the power switch on (IG).
(c) Using an oscilloscope, check the waveform.
OK:
Waveform is similar to that shown in the illustration.
|
Item |
Content |
|---|---|
|
Terminal No. |
I49-7 (LIN1) - Body ground |
|
Tool Setting |
2 V/DIV., 20 ms./DIV. |
|
Condition |
Power switch on (IG) |
| OK |
|
| NG |
|
|
|