U1131

MULTIPLEX COMMUNICATION: LIN COMMUNICATION SYSTEM: U1131: Lost Communication with Rear Climate Control Seat ECU LH

DTC U1131 - Lost Communication with Rear Climate Control Seat ECU LH

DESCRIPTION

This DTC is output when LIN communication between the rear seat climate control ECU LH and rear power seat module switch stops for 10 seconds or more.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: When using the intelligent tester or Techstream with the power switch OFF to troubleshoot:

Connect the intelligent tester or Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the tester and vehicle begins.
HINT: When DTC U0211, U0246, U1130 and U1131 are output simultaneously, perform troubleshooting for "Rear Side Switch Module LIN Communication Malfunction" first Rear 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.

Result:





B -- USE SIMULATION METHOD TO CHECK
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (REAR POWER SEAT SWITCH - SEAT CLIMATE CONTROL ECU)





(a) Disconnect the z54*1 or S15*2 module switch connector.
(b) Disconnect the f13*3 or f28*4 ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
(1) w/o Climate Control Seat System
Standard resistance:

w/o Ottoman:





w/ Ottoman:





Standard voltage:

w/o Ottoman:





w/ Ottoman:





(2) w/ Climate Control Seat System
Standard resistance:

w/o Ottoman:





w/ Ottoman:





Standard voltage:

w/o Ottoman:





w/ Ottoman:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (SEAT CLIMATE CONTROL ECU - BATTERY AND BODY GROUND)





(a) Disconnect the f13*1 or f28*2 ECU connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard voltage:

w/ Climate Control Seat System:





w/o Climate Control Seat System:





Standard voltage:

w/ Climate Control Seat System:





w/o Climate Control Seat System:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. CHECK REAR SEAT CLIMATE CONTROL ECU LH (OPERATION)
(a) Temporarily replace the rear seat climate control ECU LH with a new or normally functioning one.
(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.

Result:





A -- REPLACE REAR POWER SEAT MODULE SWITCH
B -- END (REAR SEAT CLIMATE CONTROL ECU LH IS DEFECTIVE)