B1273

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

DTC B1273 - Sliding Roof ECU Communication Stop

DESCRIPTION

This DTC is output when LIN communication between the sliding roof ECU (sliding roof drive gear sub-assembly) and main body ECU (instrument panel junction block assembly) stops for more than 10 seconds.

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTICE: When using the Techstream with the engine switch off to troubleshoot:

Connect the Techstream to the vehicle, and turn the courtesy switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.

PROCEDURE

1. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for DTC.
OK:
B1273 is not output.
NG -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU)
OK -- USE SIMULATION METHOD TO CHECK
2. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU)
(a) Disconnect the E8 and Q12 connectors.

(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SLIDING ROOF ECU - BATTERY AND GROUND)

(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:

(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. REPLACE SLIDING ROOF ECU (SLIDING ROOF DRIVE GEAR SUB-ASSEMBLY)
(a) Replace the sliding roof ECU (Sliding roof drive gear sub-assembly) Removal.
NEXT -- Continue to next step.
5. CHECK FOR DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Recheck for DTC.
OK:
B1273 is not output.
NG -- REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
OK -- END (SLIDING ROOF ECU IS DEFECTIVE)