Dtc U0208 Lost Communication With Seat Control Module A

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

RECONFIRM DTC OUTPUT

CHECK FOR OPEN IN CAN BUS WIRE (POWER SEAT SWITCH ASSEMBLY CAN BRANCH WIRE)

CHECK HARNESS AND CONNECTOR (POWER SEAT SWITCH ASSEMBLY - BATTERY AND BODY GROUND)

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

1. Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output (Click here).
   
2. Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
   
3. After turning the ignition switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work (Click here).
   
4. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
   
5. After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
   
6. DTC check procedure: Turn the ignition switch to ON and wait at least 20 seconds.
   
7. After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed (Click here).
   

HINT:

1. Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
   
2. Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.
   

1. Reconfirm DTCs.
   

   HINT:

   If DTC U1002 is output from Gateway of the main body ECU (multiplex network body ECU), this indicates a sub bus 1 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 1.

   Result

   Result	Proceed to
   DTC U1002 is not output from main body ECU (multiplex network body ECU).	A
   DTC U1002 is output from main body ECU (multiplex network body ECU).	B

1. Disconnect the cable from the negative (-) battery terminal.
   

2. Disconnect the power seat switch assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   c40-8 (MPX1) - c40-7 (MPX2)	Cable disconnected from negative (-) battery terminal	54 to 69 Ω

   Text in Illustration

   *a	Rear view of wire harness connector (to Power Seat Switch Assembly)

1. Connect the cable to the negative (-) battery terminal.
   

   NOTICE:

   When connecting the cable, some systems need to be initialized after the cable is reconnected (Click here).

2. Disconnect the power seat switch assembly connector.
   

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

   Standard Voltage:

   Tester Connection	Condition	Specified Condition
   c39-6 (+B) - Body ground	Always	11 to 14 V
   c40-12 (SYSB) - Body ground	Always	11 to 14 V

4. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   c39-1 (GND) - Body ground	Always	Below 1 Ω