Inspection Procedure

WARNING: This page is about a different car, the 2005 Lexus GS 430 and 2005 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminals +B and GND of Power Seat Position ECU connector.
PREPARATION:

Remove Power Seat Position ECU with connectors still connected.

CHECK:

Measure voltage between terminals +B and GND of Power Seat Position ECU connector.

OK:

Voltage: 10 - 14 V

Fig 1: Measuring Voltage Between Terminals +B And GND Of ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Proceed to next circuit inspection shown in problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG: Go to next step.
Check continuity between terminal GND of Power Seat Position ECU connector and body ground.
CHECK:

Measure resistance between terminal GND of Power Seat Position ECU and body ground.

OK:

Resistance: Continuity (below 1 Ω)

Fig 2: Measuring Resistance Between Terminal GND & Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Repair or replace harness or connector.
2. OK: Go to next step.
Check voltage between terminals SYSB and SGND of Power Seat Position ECU connector.
PREPARATION:

Remove Power Seat Position ECU with connectors still connected.

CHECK:

Measure voltage between terminals SYSB and SGND of Power Seat Position ECU connector.

OK:

Voltage: 10 - 14 V

Fig 3: Measuring Voltage Between Terminal SYSB And SGND Of ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Proceed to next circuit inspection shown in problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
2. NG: Go to next step.
Check continuity between terminal SGND of Power Seat Position ECU connector and body ground.
CHECK:

Measure resistance between terminals SGND of Power Seat Position ECU and body ground.

OK:

Resistance: Continuity (below 1 Ω)

Fig 4: Measuring Resistance Between SGND Terminal & Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Repair or replace harness or connector.
2. OK: Go to next step.
Check SEAT-FR and DOME Fuse.
1. NG: Check for short in all the harness and components connected to SEAT-FR and DOME fuse, and repair them (See attached wiring diagram).
2. OK: Check and repair connector between Power Seat Position ECU and battery.