RM35X0E _57 Power Source / Network _078518 NETWORKING _0388279 LIN COMMUNICATION SYSTEM C

NETWORKING  LIN COMMUNICATION SYSTEM  B2785  Communication Malfunction between ECUs Connected by LIN  


DESCRIPTION

If the certification ECU (smart key ECU assembly) detects a communication error with an ECU connected to the certification bus lines for 7 seconds or more, DTC B2785 will be stored.

DTC No. Detection Item DTC Detection Condition Trouble Area
B2785 Communication Malfunction between ECUs Connected by LIN
·

Errors in LIN communication between ECUs or an open or short in communication lines.

·

The certification ECU (smart key ECU assembly) detects a communication error with an ECU connected to the certification bus lines for 7 seconds or more.


·

Certification ECU (smart key ECU assembly)

·

Steering lock ECU (steering lock actuator or upper bracket assembly)

·

ID code box (immobiliser code ECU)

·

Harness or connector



WIRING DIAGRAM

B486902E16
0.375,1.49 0.823,1.75 0.448,0.26 10 false N156 0.365,1.646 1.885,2.104 1.521,0.458 10 false Certification ECU (Smart Key ECU Assembly) 1.667,0.958 2.115,1.219 0.448,0.26 10 false LIN 4.385,1.469 5.375,1.729 0.99,0.26 10 false N157 4.375,1.635 7.052,2.167 2.677,0.531 10 false Steering Lock ECU (Steering Lock Actuator or Upper Bracket Assembly) 5.208,3.313 5.656,3.573 0.448,0.26 10 false N158 5.188,3.49 6.771,3.917 1.583,0.427 10 false ID Code Box (Immobiliser Code ECU) 0.719,4.333 2.49,4.813 1.771,0.479 10 false : LIN Communication Line 5.094,2.646 5.542,2.906 0.448,0.26 10 false 2 5.094,0.792 5.542,1.052 0.448,0.26 10 false 5 1.99,0.802 2.438,1.063 0.448,0.26 10 false 13 5.292,0.948 5.74,1.208 0.448,0.26 10 false LIN 5.281,2.781 5.729,3.042 0.448,0.26 10 false LIN1

CAUTION / NOTICE / HINT

NOTICE:
·

Before performing the inspection, check that DTC B2786 or B278C is not output.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

·

When using the GTS with the ignition switch off, connect the GTS to the DLC3 and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Smart Key. While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

·

Before replacing the certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator or upper bracket assembly), refer to the Service Bulletin.

Click hereVehicle Interior>THEFT DETERRENT / KEYLESS ENTRY>ENTRY AND START SYSTEM (for Entry Function)>PRECAUTION



PROCEDURE

1.CHECK FOR DTC
a.

Clear the DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Clear DTCs
50002 125

b.

Recheck for DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Trouble Codes
50001 125

Result:
Result Proceed to
DTC B2785 is output A
DTC B2785 is not output B



A

2.CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

B

USE SIMULATION METHOD TO CHECK

Click hereGeneral>INTRODUCTION>HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS>HOW TO PROCEED WITH TROUBLESHOOTING


2.CHECK STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)
a.

Disconnect the N157 steering lock ECU (steering lock actuator or upper bracket assembly) connector.


b.

Clear the DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Clear DTCs
50002 125

c.

Recheck for DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Trouble Codes
50001 125

Result:
Result Proceed to
DTC B2785 is output A
DTC B2785 is not output B



A

3.CHECK ID CODE BOX (IMMOBILIZER CODE ECU)

B

REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR OR UPPER BRACKET ASSEMBLY)

Click hereSteering>STEERING COLUMN>STEERING COLUMN ASSEMBLY>DISASSEMBLY


3.CHECK ID CODE BOX (IMMOBILIZER CODE ECU)
a.

Disconnect the N158 ID code box (immobilizer code ECU) connector.


b.

Clear the DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Clear DTCs
50002 125

c.

Recheck for DTCs.

Click herePower Source / Network>NETWORKING>LIN COMMUNICATION SYSTEM>DTC CHECK / CLEAR

Body Electrical > Entry&Start > Trouble Codes
50001 125

Result:
Result Proceed to
DTC B2785 is output A
DTC B2785 is not output B



A

4.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - EACH ECU)

B

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU)

4.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - EACH ECU)
a.

Disconnect the N156 certification ECU (smart key ECU assembly) connector.


b.

Disconnect the N157 steering lock ECU (steering lock actuator or upper bracket assembly) connector.


c.

Disconnect the N158 ID code box (immobiliser code ECU) connector.


d.

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

Standard Resistance:
Tester Connection Condition Specified Condition
N156-13 (LIN) - N157-5 (LIN) Always Below 1 Ω
N156-13 (LIN) - N158-2 (LIN1) Always Below 1 Ω
N156-13 (LIN), N157-5 (LIN) or N158-2 (LIN1) - Body ground Always 10 kΩ or higher



Result:
Proceed to
OK
NG



OK

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR