Toyota 4Runner: Lost Communication with "Seat Control Module A" (U0208)

Toyota 4Runner Service Manual / Power Source / Network / Networking / Can Communication System / Lost Communication with "Seat Control Module A" (U0208)

DESCRIPTION

DTC Code	DTC Detection Condition	Trouble Area
U0208	There is no communication from the front power seat switch LH.	Power source or inside front power seat switch LH Front power seat switch LH branch wire or connector Front power seat switch LH

HINT:

For vehicles with a seat position memory only.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

Operating the ignition switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1.	DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL

(a) Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and branch wire.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See page ).

2.	CHECK FOR OPEN IN CAN BUS WIRE (FRONT POWER SEAT SWITCH LH BRANCH WIRE)

(a) Disconnect the b19 front power seat switch LH connector.

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

Standard Resistance:

Tester Connection	Switch Condition	Specified Condition
b19-8 (CANP) - b19-7 (CANN)	Ignition switch off	54 to 69 Ω

Text in Illustration

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

REPAIR OR REPLACE FRONT POWER SEAT SWITCH LH CAN BRANCH WIRE OR CONNECTOR (CANP, CANN)

3.	CHECK HARNESS AND CONNECTOR (FRONT POWER SEAT SWITCH LH - BATTERY AND BODY GROUND)

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

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See page ).

(b) Disconnect the b18 front power seat switch LH connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
b18-2 (GND1) - Body ground	Always	Below 1 Ω

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
b18-7 (+B1) - Body ground	Always	11 to 14 V
b19-12 (SYSB) - Body ground	Always	11 to 14 V

Text in Illustration

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

REPLACE FRONT POWER SEAT SWITCH LH

REPAIR OR REPLACE HARNESS OR CONNECTOR

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