Lexus NX: Lost Communication with Front Panel LIN (B14B2)
DESCRIPTION
The air conditioning control assembly communicates with the air conditioning amplifier assembly through the LIN communication system.
If the LIN communication system malfunctions, the air conditioning amplifier assembly does not operate even if the air conditioning control assembly is operated.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Memory | Note |
|---|---|---|---|---|---|
| B14B2 | Lost Communication with Front Panel LIN | Lost communication with the air conditioning control assembly. |
| Memorized (10 seconds or more) | - |
HINT:
The air conditioning amplifier assembly stores the DTC of the respective malfunction if it 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.
-
When the auxiliary battery is disconnected or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.
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PROCEDURE
| 1. | CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - BATTERY AND BODY GROUND) |
| (a) Disconnect the air conditioning control assembly connector. |
|
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
| I13-8 (IG+) - Body ground | Power switch off | Below 1 V |
| Power switch on (IG) | 11 to 14 V |
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I13-14 (GND) - Body ground | Always | Below 1 Ω |
| NG | .gif) | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
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| 2. | CHECK HARNESS AND CONNECTOR (AIR CONDITIONING CONTROL ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY) |
(a) Disconnect the I13 air conditioning control assembly connector.
(b) Disconnect the I50 air conditioning amplifier assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| I13-6 (LIN1) - I50-37 (LIN1) | Always | Below 1 Ω |
| I13-6 (LIN1) or I50-37 (LIN1) - Body ground | Always | 10 kΩ or higher |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
| 3. | CHECK AIR CONDITIONING CONTROL ASSEMBLY |
(a) Replace the air conditioning control assembly.
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(b) Check the air conditioning control assembly operates normally.
HINT:
Since the air conditioning control assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning control assembly with a new or known good one and check that the condition returns to normal.
OK:
Air conditioning control assembly operation returns to normal.
| Result | Proceed to |
|---|---|
| OK | A |
| NG (When troubleshooting according to Problem Symptoms Table) | B |
| NG (When troubleshooting according to the DTC) | C |
| A | | END (AIR CONDITIONING CONTROL ASSEMBLY IS DEFECTIVE) |
| B | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| C | | REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY |
READ NEXT:
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SEE MORE:
Removal
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Terminals Of Ecu
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