B1271

MULTIPLEX COMMUNICATION SYSTEM: B1271: Combination Meter ECU Communication Stop

DTC B1271 - Combination Meter ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the combination meter 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 (B1266 and B1267) are detected at the same time as "communication stop" DTC B1271, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (DOME, MPX-B)
(a) Remove the DOME and MPX-B fuses from the engine room J/B No. 1.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (COMBINATION METER ECU - BATTERY AND BODY GROUND)





(a) Disconnect the J34 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 J34, J49, J76, A27 and J58 ECU connectors.
(b) Measure the resistance between the specified terminals on the wire harness side connectors.
Standard resistance:





*1: w/ Adaptive front-lighting system
*2: w/o Adaptive front-lighting system
*3: w/ Tire Pressure Warning System
*4: w/o Tire Pressure Warning System
Result:






C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPLACE COMBINATION METER ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE COMBINATION METER ECU