B1272

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1272: Power Seat ECU Communication Stop
B1272 - Power Seat ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the position control ECU and switch (driver seat ECU) and multiplex network gateway ECU stops for more than 10 seconds.





WIRING DIAGRAM





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 B1272, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (FR P/SEAT LH, MPX-B)

(a) Remove the FR P/SEAT LH fuse from the cowl side J/B LH.

(b) Remove the MPX-B fuse from the engine room J/B No. 1.

(c) Measure the resistance of the fuse.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

2. CHECK WIRE HARNESS (POSITION CONTROL ECU AND SWITCH - BATTERY AND BODY GROUND)

(a) Disconnect the U7 and U6 ECU connector.





(b) Measure the voltage and resistance of the wire harness side connector

Standard voltage:





Standard resistance:





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

3. CHECK RESISTANCE OF COMMUNICATION LINE

(a) Disconnect the 2F and J55 ECU connectors.





(b) Measure the resistance between the specified terminals on the wire harness side connectors.

Standard resistance:





Result:





B -- REPAIR OR REPLACE HARNESS OR CONNECTOR AND REPLACE POSITION CONTROL ECU

C -- REPAIR OR REPLACE HARNESS OR CONNECTOR

A -- REPLACE POSITION CONTROL ECU AND SWITCH