LIN Communication System

MULTIPLEX COMMUNICATION: LIN COMMUNICATION SYSTEM: U1127: Lost Communication with Center Console Switch ECU
U1127 - Lost Communication with Center Console Switch ECU

DESCRIPTION

This DTC is output when LIN communication between the outer mirror switch and No. 1 console switch stops for 10 seconds or more.





WIRING DIAGRAM





INSPECTION PROCEDURE

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

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

HINT
When DTC U1127, U1128 and U1129 are output simultaneously, perform troubleshooting for "Driver Side Switch Module LIN Communication Malfunction" first Driver Side Switch Module LIN Communication Malfunction.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Recheck for DTC Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC U1127 is not output.

NG -- CHECK HARNESS AND CONNECTOR (OUTER MIRROR SWITCH - NO. 1 CONSOLE SWITCH)

OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting

3. CHECK HARNESS AND CONNECTOR (OUTER MIRROR SWITCH - NO. 1 CONSOLE SWITCH)

(a) Disconnect the L6 and L75 switch connectors.





(b) Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance:





Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK NO. 1 CONSOLE SWITCH (BATTERY VOLTAGE AND GROUND)

(a) Disconnect the L75 switch connector.





(b) Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance:





Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE NO. 1 CONSOLE SWITCH

(a) Temporarily replace the No. 1 console switch with a new or normally functioning one.

w/o Rear Entertainment System: Disassembly

w/ Rear Entertainment System: Disassembly

(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

6. CHECK FOR DTC

(a) Recheck for DTC Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC U1127 is not output.

NG -- REPLACE OUTER MIRROR SWITCH Removal

OK -- END (NO. 1 CONSOLE SWITCH IS DEFECTIVE)