U1131

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





HINT
For vehicles with seat heater system or climate control seat system only.

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 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.

OK:

DTC U1131 is not output.

NG -- CHECK HARNESS OR CONNECTOR (REAR POWER SEAT SWITCH - SEAT CLIMATE CONTROL ECU LH)

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

3. CHECK HARNESS OR CONNECTOR (REAR POWER SEAT SWITCH - SEAT CLIMATE CONTROL ECU LH)

(a) w/ Climate Control Seat System:

(1) Disconnect the r2*1 or S15*2 module switch connector.

HINT
*1: except 4-Passenger with Ottoman

*2: for 4-Passenger with Ottoman





(2) Disconnect the f28 ECU connector.

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

Standard resistance:

except 4-Passenger with Ottoman:





for 4-Passenger with Ottoman:





Standard voltage:

except 4-Passenger with Ottoman:





for 4-Passenger with Ottoman:





(b) w/ Seat Heater System:

(1) Disconnect the r2*1 or S15*2 module switch connector.

HINT
*1: except 4-Passenger with Ottoman

*2: for 4-Passenger with Ottoman





(2) Disconnect the f13 ECU connector.

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

Standard resistance:

except 4-Passenger with Ottoman:





for 4-Passenger with Ottoman:





Standard voltage:

except 4-Passenger with Ottoman:





for 4-Passenger with Ottoman:





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

4. CHECK REAR SEAT CLIMATE CONTROL ECU LH (BATTERY VOLTAGE AND GROUND)

(a) w/ Climate Control Seat System:

(1) Disconnect the f28 ECU connector.





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

Standard resistance:





Standard voltage:





(b) w/ Seat Heater System:

(1) Disconnect the f13 ECU connector.





(2) 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 REAR SEAT CLIMATE CONTROL ECU LH

(a) Temporarily replace the rear seat climate control ECU LH with a new or normally functioning one.

except Ottoman: Disassembly

for Ottoman: Reassembly

(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 U1131 is not output.

Result





B -- REPLACE REAR POWER SEAT MODULE SWITCH Disassembly

C -- REPLACE REAR POWER SEAT MODULE SWITCH Disassembly

A -- END (REAR SEAT CLIMATE CONTROL ECU LH IS DEFECTIVE)