B1294

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1294: Immobiliser ECU Communication Stop

DTC B1294 - Immobiliser ECU Communication Stop

DESCRIPTION

DTC B1294 is output when communication between the transponder key ECU (immobiliser ECU) and the gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT: When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1279, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (ALT, INP-J/B, MPX-B)
(a) Remove the ALT and INP-J/B (*1) fuses from the fusible link block.
HINT: *1: without Air Suspension System
(b) Remove the MPX-B fuse from the instrument panel J/B.
(c) Measure the resistance of the fuses.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND)
(a) Disconnect the T9 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 T9, B5 and G3 ECU connectors.
(b) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result:






C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR AND REPLACE TRANSPONDER ECU ASSEMBLY
A -- REPLACE TRANSPONDER KEY ECU