Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001FPEG
Model Year Start: 2019 Model: RAV4 Prod Date Range: [11/2018 -           ]
Title: HEATING / AIR CONDITIONING: AIR CONDITIONING SYSTEM (for Gasoline Model): B14B2; Lost Communication with Front Panel LIN; 2019 - 2024 MY RAV4 [11/2018 -        ]

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 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

B14B2

Lost Communication with Front Panel LIN

Lost communication with air conditioning control assembly

  • Diagnosis condition: Ignition switch ON
  • Malfunction status: Lost communication with air conditioning control assembly
  • Detection time: Continuously for 10 seconds or more
  • Harness or connector
  • Air conditioning control assembly
  • Air conditioning amplifier assembly

Memorized

WIRING DIAGRAM

w/ Stop and Start System:
w/o Stop and Start System:

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 - BATTERY AND BODY GROUND)

(a) Disconnect the air conditioning control assembly connector.

*a

Front view of wire harness connector

(to Air Conditioning Control Assembly)

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

G24-13 (GND) - Body ground

Always

Below 1 Ω

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

w/ Stop and Start System

Tester Connection

Switch Condition

Specified Condition

G24-9 (IG+) - Body ground

Ignition switch ON

10.5 to 16 V

Ignition switch off

Below 1 V

w/o Stop and Start System

Tester Connection

Switch Condition

Specified Condition

G24-9 (IG+) - Body ground

Ignition switch ON

11 to 14 V

Ignition switch off

Below 1 V

Result

Proceed to

OK

A

NG (w/ Stop and Start System)

B

NG (w/o Stop and Start System)

C
B

GO TO STOP AND START SYSTEM 2019 - 2023 MY RAV4 [11/2018 - 10/2023]; STOP AND START: STOP AND START SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2024 MY RAV4 [10/2023 -        ]; STOP AND START: STOP AND START SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

C

REPAIR OR REPLACE HARNESS OR CONNECTOR
A

2.

CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONING CONTROL ASSEMBLY)

(a) Disconnect the G24 air conditioning amplifier assembly connector.

(b) Disconnect the G46 air conditioning control assembly connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

G24-7 (LIN1) - G46-7 (LIN1)

Always

Below 1 Ω

G24-7 (LIN1) or G46-7 (LIN1) - Other terminals and body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

3.

CHECK AIR CONDITIONING CONTROL ASSEMBLY (OUTPUT)

(a) Using an oscilloscope, check the waveform.

Item

Content

Tester Connection

G46-7 (LIN1) - Body ground

Tool Setting

2 V/DIV., 20 μs/DIV.

Condition

Ignition switch ON

OK:

The waveform displays properly.

*a

Component with harness connected

(Air Conditioning Amplifier Assembly)
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

NG

REPLACE AIR CONDITIONING CONTROL ASSEMBLY