Dtc B1297 Clearance Sonar Ecu Communication Stop

Communication System. Lexus Is250, Is220D. Gse20 Ale20
Multiplex Communication. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT FUSE (LH-IG)

CHECK WIRE HARNESS (CLEARANCE WARNING ECU - BATTERY AND BODY GROUND)

CHECK RESISTANCE OF COMMUNICATION LINE

DTC B1297 Clearance Sonar ECU Communication Stop


DESCRIPTION

This DTC is detected when communication between the clearance warning ECU and gateway ECU stops for more than 10 seconds.

DTC No.
DTC Detection Condition
Trouble Area
B1297
Clearance warning ECU communication stops
  1. Clearance warning ECU
  2. Wire harness

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1297 Clearance Sonar Ecu Communication Stop


INSPECTION PROCEDURE

HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1297, repair the "+B or GND short malfunction of communication bus" DTCs first.
1.INSPECT FUSE (LH-IG)

  1. Remove the LH-IG fuse from the main body ECU LH (cowl side J/B LH).

  1. Measure the resistance of the fuse.

Standard resistance:
Below 1 Ω


NG
REPLACE FUSE
OK


Go to step 3

2.CHECK WIRE HARNESS (CLEARANCE WARNING ECU - BATTERY AND BODY GROUND)


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1297 Clearance Sonar Ecu Communication Stop

  1. Disconnect the Q37 ECU connector.

  1. Measure the voltage and resistance of the wire harness side connector.

    Standard voltage:
    Tester Connection
    		Condition
    		Specified Condition
    IG (Q37-8) - Body ground
    		Engine switch on (IG)
    		10 to 14 V
    Standard resistance:
    Tester Connection
    		Specified Condition
    E (Q37-27) - Body ground
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK RESISTANCE OF COMMUNICATION LINE


    Lexus Is250, Is220D. Gse20 Ale20.Multiplex Communication.Multiplex Communication System. Dtc B1297 Clearance Sonar Ecu Communication Stop

  1. Disconnect the Q37, A27, J58 and J34 ECU connectors.

  1. Measure the resistance between the specified terminals on the wire harness side connectors.

    Standard resistance:
    with Adaptive Front-Lighting System:
    Tester Connection
    		Specified Condition
    M+ (Q37-26) - MPX2 (A27-6)
    		Below 1 Ω
    M+ (Q37-26) - Body ground
    		10 kΩ or higher
    without Adaptive Front-Lighting System;
    Tester Connection
    		Specified Condition
    M+ (Q37-26) - MPX- (J58-31)
    		Below 1 Ω
    M+ (Q37-26) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE CLEARANCE WARNING ECU