Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

Steering. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
Steering Column. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK DTC (CERTIFICATION ECU)

CHECK WIRE HARNESS (LIN COMMUNICATION LINE)

CHECK OPERATION OF CERTIFICATION ECU

CHECK OPERATION OF MAIN BODY ECU

CHECK OPERATION OF STEERING LOCK ECU

DTC B2785 Communication Malfunction between ECUs Connected by LIN


DESCRIPTION

This DTC is output when LIN communication from the certification ECU stops for a certain amount of time.

DTC No.
DTC Detection Condition
Trouble Area
B2785
LIN communication from certification ECU stops for certain amount of time
  1. Open or short in wire harness between ECUs
  1. Wire harness
  2. Certification ECU
  3. ID code box
  4. Instrument panel junction block (Main body ECU)
  5. Steering lock ECU (Steering lock actuator)

WIRING DIAGRAM


Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.Steering Column.Steering System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin


INSPECTION PROCEDURE

HINT:
When the engine switch is off, the main body ECU may occasionally go into a non-active state called sleep mode. Therefore, before proceeding with the inspection, it is necessary to perform the following step to wake up the ECU:
Before starting the inspection, with the engine switch off, open the driver door. Then (with the engine switch still off) open and close any door several times at 1.5 second intervals.
1.CHECK DTC (CERTIFICATION ECU)

  1. Clear the DTC.

  1. Recheck for DTC.

    Result
    Result
    		Proceed to
    B2785 output reoccurs
    		A
    B2785 output does not reoccur
    		B


B
NORMAL
A


2.CHECK WIRE HARNESS (LIN COMMUNICATION LINE)

Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.Steering Column.Steering System. Dtc B2785 Communication Malfunction Between Ecus Connected By Lin

  1. Disconnect the E63 certification ECU connector.

  1. Disconnect the E6 steering lock actuator connector.

  1. Disconnect the E51 ID code box connector.

  1. Disconnect the ID instrument panel junction block connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E63-10 (LIN) - ID-9 (LIN1)
    		Below 1 Ω
    E63-10 (LIN) or ID-9 (LIN1) - Body ground
    		10 kΩ or higher
    E63-10 (LIN) - E6-5 (LIN)
    		Below 1 Ω
    E63-10 (LIN) or E6-5 (LIN) - Body ground
    		10 kΩ or higher
    E63-10 (LIN) - E51-3 (LIN1)
    		Below 1 Ω
    E63-10 (LIN) or E51-3 (LIN1) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK OPERATION OF CERTIFICATION ECU

  1. Replace the certification ECU with a normally functioning or new one.

  1. Check for DTC.

    Result
    Result
    		Proceed to
    B2785 output reoccurs
    		A
    B2785 output does not reoccur
    		B


B
REPLACE CERTIFICATION ECU
A


4.CHECK OPERATION OF MAIN BODY ECU

  1. Replace the instrument panel junction block assembly (main body ECU) with a normally functioning or new one.

  1. Check for DTC.

    Result
    Result
    		Proceed to
    B2785 output reoccurs
    		A
    B2785 output does not reoccur
    		B


B
REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)
A


5.CHECK OPERATION OF STEERING LOCK ECU

  1. Replace the steering lock actuator assembly with a normally functioning or new one.

  1. Check for DTC.

    Result
    Result
    		Proceed to
    B2785 output reoccurs
    		A
    B2785 output does not reoccur
    		B


B
REPLACE STEERING LOCK ACTUATOR ASSEMBLY
A

REPLACE ID CODE BOX