LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2008 >> IS 250 AWD >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Multiplex Communication >> Multiplex Communication System >> DTC B1296 Front Light ECU Communication Stop >> Inspection Procedure

Inspection Procedure

HINT:

When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1296, repair the "+B or GND short malfunction of communication bus" DTCs first.

  1. INSPECT FUSE (MPX-B) 
    1. Remove the MPX-B fuse from the engine room J/B No. 1.
    2. Measure the resistance of the fuse.

      Standard resistance: 

      Below 1 Ω 

    NG: REPLACE FUSE 

    OK: Go to next step 

  2. CHECK WIRE HARNESS (FRONT CONTROLLER - BATTERY AND BODY GROUND) 
    1. Disconnect the 2E and 2F ECU connectors.
    2. Measure the voltage and resistance of the wire harness side connectors.

    Standard voltage 

    TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

    Tester Connection Condition Specified Condition
    2E-4 - Body ground Always 10 to 14 V

    Standard resistance 

    TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

    Tester Connection Specified Condition
    2F-1 - Body ground Below 1 Ω
    Fig 1: Identifying 2E And 2F ECU Connector Terminals
    G05828541Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. CHECK RESISTANCE OF COMMUNICATION LINE 
    1. Disconnect the 2F, A30 and J55 ECU connectors.
    2. Measure the resistance between the specified terminals on the wire harness side connectors.

    Standard resistance 

TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART

Tester Connection Specified Condition
2F-6 - MPX2 (A30-17) Below 1 Ω
2F-5 - MPX2 (J55-24) Below 1 Ω

Result 

RESULT CHART

Result Proceed to
Both are OK A
One is OK B
Both are NG C
Fig 2: Identifying 2F, A30 And J55 ECU Connector Terminals
G05828542Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: REPAIR OR REPLACE HARNESS OR CONNECTOR AND REPLACE FRONT CONTROLLER 

C: REPAIR OR REPLACE HARNESS OR CONNECTOR 

A: REPLACE FRONT CONTROLLER