Occupant Classification System (Diagnostics - Introduction): Diagnosis Lexus LX J200

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use these procedures to troubleshoot the occupant classification system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. INSPECT BATTERY VOLTAGE Standard voltage 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding. NEXT: Go to next step
3. CUSTOMER PROBLEM ANALYSIS Confirm customer problem symptoms. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-385196-S09917434812011021400000) . NEXT: Go to next step
4. CHECK FOR DTC* Check for DTCs and note any codes that are output. Refer to «DTC CHECK / CLEAR»(ref-385313-S18166417782011021400000) . Clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-385313-S18166417782011021400000) . Recheck for DTCs. Refer to «DTC CHECK / CLEAR»(ref-385313-S18166417782011021400000) . Based on the DTCs output above, try to force output of the same CAN communication system DTC or occupant classification system DTC by simulating the symptoms indicated by the DTC. RESULT: Result Proceed to DTC is not output A CAN communication system DTC is output B Occupant classification system DTC is output C B --> Go to DIAGNOSTIC TROUBLE CODE CHART. Refer to «PRECAUTION»(ref-385222-S41286850992011021400000) C --> Go to DIAGNOSTIC TROUBLE CODE CHART. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-385313-S03723576982011021400000) A: Go to next step
5. PROBLEM SYMPTOMS TABLE Refer to the Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE»(ref-385313-S41956649492011021400000) . RESULT: Result Proceed to Fault is not listed in problem symptoms table A Fault is listed in problem symptoms table B B --> Go to step 6 A: Go to next step
6. OVERALL ANALYSIS AND TROUBLESHOOTING* Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-385313-S34436197322011021400000) Data List / Active Test. Refer to «DATA LIST / ACTIVE TEST»(ref-385313-S01735366472011021400000) NEXT: Go to next step
7. ADJUST, REPAIR OR REPLACE NEXT: Go to next step
8. CONFIRMATION TEST NEXT --> END

PROBLEM SYMPTOMS TABLE

HINT

1. Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
2. Inspect the fuses and relays related to this system before inspecting the suspected areas below.

OCCUPANT CLASSIFICATION SYSTEM

Scheme 370

1. CHECK OCCUPANT CLASSIFICATION ECU Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition c8-3 (GSP) - c8-5 (GND) G - BR Seat position sensor ground line Always Below 1 V c8-4 (SP) - c8-3 (GSP) R - G Seat position sensor signal line Engine switch on (IG) Low: 4.7 to 7.3 mA Hi: 11.4 to 17.9 mA c8-5 (GND) - Body ground BR - Body ground Occupant classification ECU ground line Always Below 1 ohms c8-6 (PS) - c8-15 (GPS) W - GR Pressure sensor signal line Engine switch on (IG) Below 1 V c8-7 (VPS) - c8-5 (GND) B - BR Pressure sensor +B line Engine switch on (IG) 4.75 to 5.25 V c8-8 (GBT) - c8-5 (GND) LG - BR Belt tension sensor ground line Always Below 1 V c8-9 (IG) - c8-5 (GND) B-R - BR Occupant classification ECU +B line Engine switch on (IG) 11 to 14 V c8-10 (DIA) - c8-5 (GND) R-G - BR Diagnosis (DLC3) Engine switch on (IG) Pulse generation c8-11 (FSR+) - c8-12 (FSR-) W - B Center airbag sensor communication line Engine switch on (IG) Pulse generation c8-12 (FSR-) - c8-5 (GND) B - BR Center airbag sensor communication line (-) Always Below 1 ohms c8-13 (BSW) - c8-14 (BGND) R-B - B-W Passenger side buckle switch line Engine switch on (IG) Low: 4 to 7 mA Hi: 12 to 18 mA c8-14 (BGND) - c8-5 (GND) B-W - BR Passenger side buckle switch ground line Always Below 1 ohms c8-15 (GPS) - c8-5 (GND) GR - BR Pressure sensor ground line Always Below 1 ohms c8-16 (BT) - c8-5 (GND) P - BR Belt tension sensor signal line Engine switch on (IG) Below 1 V c8-17 (VBT) - c8-5 (GND) GR-G - BR Belt tension sensor +B line Engine switch on (IG) 4.75 to 5.25 V

Scheme 371

Scheme 372

1. SYMPTOM SIMULATION HINT: The most difficult case in troubleshooting is when no problem symptoms occur. In such a case, a thorough problem analysis must be carried out. A simulation of the same or similar conditions and environment in which the problem occurred in the customer's vehicle should be carried out. No matter how much skill or experience a technician has, troubleshooting without confirming the problem symptoms will lead to important repairs being overlooked and mistakes or delays. Vibration method: When vibration seems to be the major cause. HINT: Perform the simulation method only during the primary check period (for approximately 6 seconds after the engine switch is turned on (IG)). Slightly vibrate the part of the sensor considered to be the problem cause with your fingers and check whether the malfunction occurs. NOTE: Shaking the relays too strongly may result in open relays. Slightly shake the connector vertically and horizontally. Slightly shake the wire harness vertically and horizontally. HINT: The connector joint and fulcrum of the vibration are the major areas to be checked thoroughly.
2. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR Initial check: Turn the engine switch on (IG). The passenger airbag ON/OFF indicator ("ON" and "OFF") comes on for approximately 4 seconds, then goes off for approximately 2 seconds. Approximately 6 seconds after the engine switch is turned on (IG), the passenger airbag ON/OFF indicator will show ("ON" or "OFF") depending on the conditions listed below. Condition ON Indicator OFF Indicator Vacant Off Off Adult is seated On Off Child is seated Off On Child restraint system is set Off On Occupant classification system failure Off On HINT: The timing chart below is based on the operation of the passenger airbag ON/OFF indicator. Use the chart in order to check the indicator light circuit. When the occupant classification system has trouble, both the SRS warning light and the passenger airbag ON/OFF indicator ("OFF") come on. In this case, check for DTCs in the "Airbag System" first.
3. CHECK PASSENGER AIRBAG ON/OFF INDICATOR Turn the engine switch on (IG). Check that the passenger airbag ON/OFF indicator ("ON" and "OFF") comes on for approximately 4 seconds, then goes off for approximately 2 seconds. HINT: Refer to the table in the previous step regarding the passenger airbag ON/OFF indicator when the engine switch is turned on (IG) and approximately 6 seconds pass.

DTC CHECK / CLEAR

1. CHECK DTC Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / (desired system) / Trouble Codes. Read the DTCs.
2. CLEAR DTC Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / (desired system) / Trouble Codes. Clear the DTCs.

DATA LIST / ACTIVE TEST

1. DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time. NOTE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Occupant Detection / Data List. According to the display on the Techstream, read the "Data List". OCCUPANT DETECTION Tester Display Measurement Item/Range Normal Condition Diagnostic Note Passenger Classification Passenger classification / NG, AM50, AF05, Child or OFF NG: Data not determined AM50: Adult seated and seat in rear position AF05: Adult seated and seat in front position Child: Child seated OFF: Vacant - Passenger Buckle SW Buckle switch (passenger side) / Unset, Set or NG Set: Passenger side seat belt fastened Unset: Passenger side seat belt unfastened NG: Data is not determined - Pressure sensor output Pressure sensor output / Min.:0, Max.: 255 0 to 210 - Filtered pressure sensor output Filtered pressure sensor output / Min.: 0, Max.: 255 38 to 240 If the value is outside the range of Specified Condition for Zero Point Calibration, check whether any objects are placed on the seat cushion and that the seat cushion is fitted correctly. Thermistor temperature output Thermistor temperature output / Min.: -40°C (-40°F), Max.: 90°C (194°F) -40 to 85°C (-40 to 185°F) If the value is outside the range of Specified Condition for Zero Point Calibration, adjust the temperature to the proper range by using the air conditioner, etc. Weight threshold Weight threshold / Min.: 0, Max.: 255 36 to 67 (reference value) - Filtered belt tension output Filtered belt tension output / Min.: 0, Max.: 255 39 to 229 - Empty threshold value from the seat factory Empty threshold value from seat factory / Min.: 0, Max.: 255 38 to 75 - Allow threshold Threshold value for adult passenger or not from seat factory / Min.: 0, Max.: 255 43 to 64 (reference value) - Number of Present DTC Number of stored trouble codes / Min.: 0, Max.: 255 0 - Number of Past DTC Number of past trouble codes / Min.: 0, Max.: 255 0

DIAGNOSTIC TROUBLE CODE CHART

HINT

1. When DTC B1650/32 is output as a result of troubleshooting for the "Airbag System", perform troubleshooting for the "Occupant Classification System" as shown in the chart below.

1. Use the Techstream to read and clear the DTC of the occupant classification ECU, otherwise the DTCs cannot be read and cleared.

OCCUPANT CLASSIFICATION SYSTEM