B1273

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 and network gateway ECU stops for more than 10 seconds.

WIRING DIAGRAM

INSPECTION PROCEDURE
HINT: When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTCB1273, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. CHECK OPERATION
(a) Check that the tilt or slide switch can operate the sliding roof normally.
HINT: With this inspection, the sliding roof dive gear (sliding roof control ECU) CPU can be diagnosed if it works normally or not.

OK:
Tilt or slide switch can operate sliding roof normally.
OK -- CHECK RESISTANCE OF COMMUNICATION LINE
NG -- Continue to next step.
2. INSPECT FUSE (S/ROOF)
(a) Remove the S/ROOF fuse from the instrument panel block.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND)

(a) Disconnect the M12 ECU connector.
(b) Measure the voltage of the wire harness side connector.
Standard voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK RESISTANCE OF COMMUNICATION LINE
(a) Disconnect the G3 and C8 ECU connectors (with LEXUS navigation system).
(b) Disconnect the C4 and C8 ECU connectors (without LEXUS navigation system).

*1: with LEXUS Navigation System
*2: without LEXUS Navigation System
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR OR OVERHEAD J/B
OK -- REPLACE SLIDING ROOF CONTROL ECU