Steering Column

STEERING COLUMN: STEERING LOCK SYSTEM: B2785: Communication Malfunction between ECUs Connected by LIN
B2785 - Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

The certification ECU intermittently monitors the LIN communication bus between the components related to certification. DTC B2785 is output when a malfunction in the LIN communication bus between the components related to certification is detected continuously 3 times.

WIRING DIAGRAM

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 steps to wake up the ECU:

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.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - STEERING LOCK ECU)

(a) Disconnect the E84 and E77 ECU connectors.

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

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. CHECK FOR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Reconnect the E84 ECU connector.

(c) Recheck for DTCs.

OK:

B2785 does not reoccur.

NG -- REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)
OK -- Continue to next step.

3. CHECK FOR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Reconnect the E77 ECU connector.

(c) Disconnect the 1D ECU connector.

(d) Recheck for DTCs.

OK:

B2785 does not reoccur.

NG -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)
OK -- Continue to next step.

4. CHECK FOR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Reconnect the 1D ECU connector.

(c) Disconnect the E79 ECU connector.

(d) Recheck for DTCs.

OK:

B2785 does not reoccur.

NG -- REPLACE ID CODE BOX

OK -- REPLACE ECU AGGREGATION BOX ASSEMBLY (CERTIFICATION ECU) Removal

5. REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

(a) Temporarily replace the steering lock ECU with a new one Removal.

NOTICE:
When replacing the steering lock ECU, registration must be performed according to the "Registration" procedures Engine Immobiliser System (W/ Smart Key System).

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

6. CHECK FOR DTC

(a) Recheck for DTCs.

OK:

B2785 does not reoccur.

NG -- REPLACE ECU AGGREGATION BOX ASSEMBLY (CERTIFICATION ECU) Removal

OK -- END (STEERING LOCK ECU IS DEFECTIVE)

7. REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)

(a) Temporarily replace the main body ECU (instrument panel junction block) with a new or normally functioning one.

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

8. CHECK FOR DTC

(a) Recheck for DTCs.

OK:

B2785 does not reoccur.

NG -- REPLACE ECU AGGREGATION BOX ASSEMBLY (CERTIFICATION ECU) Removal

OK -- END (MAIN BODY ECU IS DEFECTIVE)

9. REPLACE ID CODE BOX

(a) Temporarily replace the ID code box with a new one Removal.

NOTICE:
When replacing the ID code box, registration must be performed according to the "Registration" procedures Engine Immobiliser System (W/ Smart Key System).

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

10. CHECK FOR DTC

(a) Recheck for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

B2785 does not reoccur.

NG -- REPLACE ECU AGGREGATION BOX ASSEMBLY (CERTIFICATION ECU) Removal

OK -- END (ID CODE BOX IS DEFECTIVE)