Lost Communication with "Seat Control Module A" (U0208)

NOTICE:

• Turn the ignition switch off before measuring the resistances between CAN bus main wires and between CAN bus branch wires.
• Turn the ignition switch off before inspecting CAN bus wires for a ground short.
• After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
• Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.

HINT:

• Operating the ignition switch, any other switches or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
• 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 DTC OUTPUT

(a) Reconfirm DTCs.

HINT:

If CAN MS bus DTC U1002 is output from the main body ECU (Techstream display: Main Body), troubleshoot for U1002 and check for malfunctions in the CAN MS bus circuit.

B

GO TO CIRCUITS INDICATED BY OUTPUT DTCS

A

1. CHECK FOR OPEN IN CAN BUS WIRES (POSITION CONTROL ECU AND SWITCH ASSEMBLY BRANCH WIRE)

(a) Turn the ignition switch off.

(b) Disconnect the position control ECU and switch assembly connector. Text in Illustration *1 Front view of wire harness connector (to Position Control ECU and Switch Assembly)

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

Standard Resistance:

NG

REPAIR OR REPLACE CAN BUS BRANCH WIRE OR CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY BRANCH WIRE)

OK

1. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

(a) Disconnect the position control ECU and switch assembly connector. Text in Illustration *1 Front view of wire harness connector (to Position Control ECU and Switch Assembly)

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

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK

1. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)

(a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition T10-1 (GND) - Body ground Always Below 1 Ω Text in Illustration *1 Front view of wire harness connector (to Position Control ECU and Switch Assembly)

OK

REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)