Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus LS 600hL. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: After the power switch is turned OFF, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the power switch OFF, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.

HINT:

If troubleshooting (wire harness inspection) is difficult to perform, remove the passenger seat installation bolts to see the undersurface of the seat cushion.
In the above case, hold the seat so that it does not fall down.
After performing the zero point calibration, check for DTCs to confirm that the calibration is completed normally. (If it fails, DTC B1797 will be output.)

CHECK FOR DTC
1. Turn the power switch ON (IG)
2. Clear the DTCs stored in the occupant classification ECU (see DIAGNOSIS SYSTEM ).
3. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
4. Turn the power switch OFF.
5. Turn the power switch ON (IG).
6. Check for the DTCs (see DIAGNOSIS SYSTEM ).
  OK: DTCs B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than DTCs B1774 and B1775 may be output at this time, but they are not related to this check
NG: Go to step 2

OK: USE SIMULATION METHOD TO CHECK (See TERMINALS OF ECU )
CHECK CONNECTION OF CONNECTOR
1. Turn the power switch OFF.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Check that the connectors are properly connected to the occupant classification ECU and the occupant detection sensor
  OK: Connectors are properly connected.
NG: CONNECT CONNECTORS PROPERLY

OK: Go to next step
CHECK CONNECTOR
1. Disconnect the connectors from the occupant classification ECU and the occupant detection sensor
2. Check that the connectors (on the center airbag sensor and occupant detection sensor side) are not damaged
  OK: Connectors are not deformed or damaged.
NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FRONT SEAT WIRE RH (OCCUPANT DETECTION SENSOR - OCCUPANT CLASSIFICATION ECU)

Connect the negative (-) terminal cable to the battery
Turn the power switch ON (IG)

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

Standard voltage

VOLTAGE SPECIFICATION

Tester Connection	Switch Condition	Specified Condition
e10-6 (PS) - Body ground	Power switch ON (IG)	Below 1 V
e10-7 (VPS) - Body ground
e10-15 (GPS) - Body ground

Turn the power switch OFF
Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds
Using 2 service wires, connect terminals 1 (VPS) and 3 (GPS), and connect terminals 2 (PS) and 3 (GPS) of connector C
NOTE: Do not forcibly insert the service wires into the terminals of the connector when connecting the wire.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
e10-6 (PS) - e10-7 (VPS)	Always	Below 1 Ω
e10-7 (VPS) - e10-15 (GPS)	Always	Below 1 Ω

Fig 1: Checking Front Seat Wire RH (Occupant Detection Sensor - Occupant Classification ECU)

Disconnect the service wires from connector C.

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

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Condition	Specified Condition
e10-6 (PS) - Body ground	Always	1 MΩ or higher
e10-7 (VPS) - Body ground
e10-15 (GPS) - Body ground
e10-6 (PS) - e10-15 (GPS)
e10-7 (VPS) - e10-15 (GPS)

NG: REPLACE FRONT SEAT WIRE RH

OK: Go to next step

CHECK FOR DTC
1. Connect the connectors to the occupant classification ECU and the occupant detection sensor.
2. Connect the negative (-) terminal cable to the battery.
3. Turn the power switch ON (IG).
4. Clear the DTCs stored in the occupant classification ECU (see DIAGNOSIS SYSTEM ).
5. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
6. Turn the power switch OFF.
7. Turn the power switch ON (IG).
8. Check for the DTCs (see DIAGNOSIS SYSTEM ).
  OK: DTCs B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than DTCs B1774 and B1775 may be output at this time, but they are not related to this check.
NG: Go to step 6

OK: USE SIMULATION METHOD TO CHECK (See TERMINALS OF ECU )
REPLACE FRONT SEAT SET (OCCUPANT DETECTION SENSOR)
1. Turn the power switch OFF.
2. Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
3. Replace the front seat set (with occupant classification ECU and occupant detection sensor) (see DISASSEMBLY ).
  HINT:
  
  Perform the inspection using parts from a normal vehicle if possible.
4. Connect the negative (-) terminal cable to the battery.
5. Turn the power switch ON (IG).
6. Clear the DTCs stored in the occupant classification ECU (see DIAGNOSIS SYSTEM ).
7. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
8. Turn the power switch OFF.
9. Turn the power switch ON (IG).
10. Check for the DTCs (see DIAGNOSIS SYSTEM ).
  OK: DTCs B1774 and B1775 are not output.
  
  HINT:
  
  Codes other than DTCs B1774 and B1775 may be output at this time, but they are not related to this check.
PERFORM ZERO POINT CALIBRATION
1. Connect the intelligent tester or Techstream to the DLC3.
2. Turn the power switch ON (IG)
3. Using the intelligent tester or Techstream, perform zero point calibration (see INITIALIZATION ).
4. Turn the power switch OFF.
5. Turn the power switch ON (IG).
6. Clear the DTCs stored in the memory (see DIAGNOSIS SYSTEM )
  HINT:
  
  If DTCs are not cleared at this time, past DTCs will remain.
CHECK FOR DTC
HINT:

Check that the zero point calibration is completed normally. If one of the following conditions is met, DTC B1797 will be output (refer to INITIALIZATION ):
- Zero point calibration is performed when the conditions for the calibration are not satisfied.
- Zero point calibration has failed
1. Turn the power switch ON (IG).
2. Clear the DTCs stored in the occupant classification ECU (see DIAGNOSIS SYSTEM ).
3. Clear the DTCs stored in the center airbag sensor (see DTC CHECK / CLEAR ).
4. Turn the power switch OFF.
5. Turn the power switch ON (IG).
6. Clear the DTCs stored in the memory (see DIAGNOSIS SYSTEM ).
  OK: DTC B1797 is not output
NG: Go to DTC B1797

OK: Go to next step
PERFORM SENSITIVITY CHECK
1. Perform the sensitivity check (see INITIALIZATION ).
NEXT: END