ECU Power Source Circuit

SEAT: FRONT POWER SEAT CONTROL SYSTEM (w/ Memory): ECU Power Source Circuit

ECU Power Source Circuit

DESCRIPTION

When a switch is activated during manual operation, all other signals are ignored, i.e. if more than one ON signal from the switches is input at one time, all of the signals are ignored. However, if the front vertical switch and lifter switch are activated simultaneously, the lifter switch operation is activated. During automatic operation, a manual switch input overrides any other operations, i.e. automatic operations stop and the manual input operation is accepted. For example, if during a seat position store/restore operation, a manual switch input is activated, the previous operation will cease and the manual operation will be performed. After the manual operation is performed, the previous automatic operation will not resume. The front power seat switch disallows the restore operation of the power seat when the system detects that the voltage at terminal SYSB is less than 8 V for 0.3 seconds. The following circuit is the power source circuit of the front power seat switch.

HINT: Manual adjustment of the slide, reclining, and lumbar support position can be performed even when the front power seat switch is not functional if current is flowing into terminals +B and SYSB.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (BATTERY - MEMORY SEAT ECU)




(a) Disconnect the front power seat switch connectors.
(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 -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (MEMORY SEAT ECU - BODY GROUND)




(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE