Section 268 (Power Seat Control System - Diagnosis): Pre-Check

1. Description This system sends a signal from the driver's seat control switch to the power seat control ECU when manual operation for seat position is performed.

   HINT:

   Indicator, etc. that indicates such as operating conditions does not exist at the infrared signal transmission and reception part.

2. Fail-safe function When infrared data communication is blocked by an object placed under the seat, etc. or the driver's seat control switch has an abnormality, the system enters fail-safe functions and only slide operation (back and forward) can be operated.
3. Clean the infrared light reception and emission part Extreme dirt on the power seat control ECU and on the reception and emission part of the infrared signal of the driver's seat control switch does not allow to send and to receive the signal. In this case, wipe the lens with a soft cloth.
   Fig 1: Checking Power Seat Control System (Driver'S Seat)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Description ECU data of this system can be read from DLC3 of the vehicle.

   Therefore when there seems to be a trouble on this system, use hand-held tester to check and troubleshoot it.

   Fig 2: Connecting Hand Held Tester To DLC3

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the DLC3.

   The vehicle's ECM uses ISO 9141 -2 for communication. The terminal arrangement of DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

   Fig 3: Identifying DLC3 Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 4: DLC3 Terminals Specified Condition Chart

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HINT:

If the display shows "UNABLE TO CONNECT TO VEHICLE" when the cable of the hand- held tester is connected to DLC3, the ignition switch is turned ON and the hand- held tester is operated, there is a problem either on the vehicle side or the tool side.

• If communication is normal when the tool is connected to another vehicle, inspect DLC3 on the original vehicle.
• If communication does not function when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

HINT:

By the DATA LIST displayed on the Hand-held tester, you can read the value of the switch, sensor, actuator and so on without removing any parts. Reading the DATA LIST as a first step of troubleshooting is one of the method to shorten the labor time.

1. Turn the ignition switch OFF.
2. Connect the hand-held tester to DLC3.
3. Turn the ignition switch ON.
4. According to the display on tester, read the "DATA LIST".

POWER SEAT CONTROL ECU: 

Fig 5: Power Seat Control ECU Data List (1 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 6: Power Seat Control ECU Data List (2 Of 2)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

MIRROR CONTROL ECU: 

Fig 7: Mirror Control ECU Data List

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

Performing ACTIVE TEST using the Hand-held tester allows the relay, and so on to operate without removing any parts. Performing ACTIVE TEST as a first step of troubleshooting is one of the method to shorten the labor time.

DATA LIST can be displayed during ACTIVE TEST.

1. Turn the ignition switch OFF.
2. Connect the Hand-held tester to DLC3.
3. Turn the ignition switch ON.
4. According to the display on tester, perform the "ACTIVE TEST".

POWER SEAT CONTROL ECU: 

Fig 8: Power Seat Control ECU Active Test

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

MIRROR CONTROL ECU: 

Fig 9: Mirror Control ECU Active Test

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002