B1273

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1273: Sliding Roof ECU Communication Stop

DTC B1273 - Sliding Roof ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the sliding roof control ECU (Moon roof control ECU) and 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 B1273, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. INSPECT FUSE (ALT, INP-J/B, ECU-B, S/ROOF)
(a) Remove the ALT, INP-J/B (*1) and ECU-B fuses from the fusible link block.
HINT: *1: without Air Suspension System
(b) Remove the S/ROOF 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. INSPECT APPARATUS
(a) Choose the apparatus to be inspected.
Result:






B -- CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)
A -- Continue to next step.
3. CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)





(a) Disconnect the M12 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.
4. CHECK RESISTANCE OF COMMUNICATION LINE





(a) Disconnect the M12 and O2 connectors.
(b) Measure the resistance between the specified terminals on the wire harness side connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- GO TO STEP 7
5. CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)





(a) Disconnect the M12 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.
6. CHECK RESISTANCE OF COMMUNICATION LINE





(a) Disconnect the M12 and O2 connectors.
(b) Measure the resistance between the specified terminals on the wire harness side connectors.
Standard resistance:






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





(a) Disconnect the O2, G3 and C4 ECU connectors.
(b) Measure the resistance between the specified terminals on the wire harness side connectors.
Standard resistance:





HINT: *1: with LEXUS Navigation System
*2: without LEXUS Navigation System

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE SLIDING ROOF CONTROL ECU