B1284

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1284: Passenger Side Junction Block ECU Communication Stop

DTC B1284 - Passenger Side Junction Block ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the passenger side junction block ECU and network gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (D/C CUT, MPX-B2)
(a) Remove the D/C CUT fuse from the engine room No. 1 relay block.
(b) Remove the MPX-B2 fuse from the passenger side junction block.
(c) Measure the resistance of the fuse.
Standard resistance:






NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (PASSENGER SIDE JUNCTION BLOCK ECU - BATTERY AND BODY GROUND)




(a) Disconnect the 3B and 3G junction block connectors.
(b) Disconnect the P4 ECU connector.
(c) Measure the voltage and resistance of the wire harness side connectors.
Standard voltage:





Standard resistance





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the 3H junction block connector.
(b) Disconnect the A21 sensor connector.
(c) Disconnect the A10 amplifier connector.
(d) Disconnect the P6 ECU connector.
(e) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result





C -- REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE PASSENGER SIDE JUNCTION BLOCK AND REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE PASSENGER SIDE JUNCTION BLOCK