ECU Power Source Circuit

DESCRIPTION

The position control ECU and switch assembly (power seat control switch and ECU) is contained in the switch assembly.
During manual operation, only one switch signal is accepted. If signals are input from 2 or more switches simultaneously, all of them are ignored, except when signals are input from the front vertical switch and lifter switch simultaneously. In this case, the signal from the lifter will operate.
During automatic operation, a manual switch input will override any other operations, i.e. automatic operations will stop and the manual input operation only will be accepted. For example, if a manual switch input is activated during a seat store/restore operation, the previous operation will cease and manual operation will be performed. After the manual operation is performed, the previous automatic operation will not resume.
The power mirror store/restore operation is unaffected by manual switch inputs.
The front power seat switch does not allow the restore operation of the power seat when the system detects that the voltage of terminal SYSB is less than 8.0 +- 0.5 V for 30 msec. or is more than 10 +- 0.5 V for 30 msec.
This circuit is the power source circuit for the position control ECU and switch assembly (power seat control switch and ECU).

HINT:

1. Manual adjustment of the slide, reclining, or lumbar can be performed even when the front power seat switch is not functional if current is allowed to flow into terminals +B and SYSB.
   

Lumbar support operation can be performed at all times.

WIRING DIAGRAM

INSPECTION PROCEDURE

1. INSPECT POSITION CONTROL ECU AND SWITCH ASSEMBLY (POWER SEAT CONTROL SWITCH AND ECU POWER SOURCE CIRCUIT)

1. Disconnect the position control ECU and switch assembly connectors.

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

   Voltage:

   Tester Connection	Condition	Specified Condition
   P30-4(IG) - Body ground	Ignition switch on	10 to 14 V
   P30-8(SYSB) - Body ground	Always	10 to 14 V
   P31-5(+B) - Body ground	Always	10 to 14 V

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK

2. INSPECT POSITION CONTROL ECU AND SWITCH ASSEMBLY (POWER SEAT CONTROL SWITCH AND ECU GROUND CIRCUIT)

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

   Resistance:

   Tester Connection	Condition	Specified Condition
   P31-1(GND) - Body ground	Always	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)

OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE