Occupant Classification System (Diagnostics - Introduction): Diagnosis Lexus HS I

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use the following procedure to troubleshoot the occupant classification system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. CUSTOMER PROBLEM ANALYSIS Confirm problem symptoms. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-398089-S18270818032011051600000) . NEXT: Go to next step
3. PASSENGER AIRBAG ON/OFF INDICATOR CHECK NEXT: Go to next step
4. DTC CHECK (Present and History DTCs) Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-398103-S42135564202011051600000) . Result Result Proceed to DTC is output. A DTC is not output. B B --> GO TO PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-398103-S31010952592011051600000) A: Go to next step
5. DTC CHART NEXT: Go to next step
6. CIRCUIT INSPECTION* NEXT: Go to next step
7. REPAIR NEXT: Go to next step
8. CLEAR DTCS (Present and History DTCs)* Clear the DTCs. Refer to «DTC CHECK / CLEAR»(ref-398103-S42135564202011051600000) . NEXT: Go to next step
9. DTC CHECK (Present and History DTCs)* Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-398103-S42135564202011051600000) . Result Result Proceed to DTC is not output. A DTC is output. B B --> GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-398103-S07988149292011051600000) A: Go to next step
10. SYMPTOM SIMULATION Check the passenger airbag ON/OFF indicator condition. Result Result Proceed to Passenger airbag ON/OFF indicator operates normally. A Passenger airbag ON/OFF indicator ("OFF") and SRS warning light come on. B B --> GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-398103-S07988149292011051600000) A: Go to next step
11. 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 1

1. OCCUPANT CLASSIFICATION ECU Terminal No. (Symbol) Wiring Color Terminal Description Condition Specification S14-1 (+B) - S14-3 (GND) BR - W-B Battery Always 11 to 14 V S14-2 (DIA) - S14-3 (GND) W - W-B Diagnosis (DLC3) Power switch on (IG) Pulse generation S14-3 (GND) - Body ground W-B - Body ground Ground Always Below 1 V S14-4 (FSR-) - S14-3 (GND) B - W-B Center airbag sensor assembly communication line Always Below 1 V S14-5 (BGND) - S14-3 (GND) R - W-B Passenger side buckle switch ground line Always Below 1 V S14-7 (IG) - S14-3 (GND) GR - W-B Power source Power switch on (IG) 11 to 14 V S14-8 (FSR+) - S14-4 (FSR-) W - B Center airbag sensor assembly communication line Power switch on (IG) Pulse generation S14-9 (BSW) - S14-5 (BGND) G - R Passenger side buckle switch line Always Pulse generation S20-1 (SGD1) - S14-3 (GND) W - W-B Front occupant classification sensor LH ground line Always Below 1 V S20-2 (SGD2) - S14-3 (GND) L - W-B Front occupant classification sensor RH ground line Always Below 1 V S20-3 (SGD3) - S14-3 (GND) L - W-B Rear occupant classification sensor LH ground line Always Below 1 V S20-4 (SGD4) - S14-3 (GND) GR - W-B Rear occupant classification sensor RH ground line Always Below 1 V S20-5 (SVC3) - S20-3 (SGD3) B - L Rear occupant classification sensor LH power supply line Power switch on (IG) 4.9 to 5.1 V S20-6 (SVC4) - S20-4 (SGD4) Y - GR Rear occupant classification sensor RH power supply line Power switch on (IG) 4.9 to 5.1 V S20-7 (SIG1) - S20-1 (SGD1) V - W Front occupant classification sensor LH signal line Power switch on (IG), a load applied to front occupant classification sensor LH 0 to 5.1 V S20-8 (SIG2) - S20-2 (SGD2) G - L Front occupant classification sensor RH signal line Power switch on (IG), a load applied to front occupant classification sensor RH 0 to 5.1 V S20-9 (SIG3) - S20-3 (SGD3) P - L Rear occupant classification sensor LH signal line Power switch on (IG), a load applied to rear occupant classification sensor LH 0 to 5.1 V S20-10 (SIG4) - S20-4 (SGD4) BR - GR Rear occupant classification sensor RH signal line Power switch on (IG), a load applied to rear occupant classification sensor RH 0 to 5.1 V S20-11 (SVC1) - S20-1 (SGD1) SB - W Front occupant classification sensor LH power supply line Power switch on (IG) 4.9 to 5.1 V S20-12 (SVC2) - S20-2 (SGD2) R - L Front occupant classification sensor RH power supply line Power switch on (IG) 4.9 to 5.1 V

Scheme 2

Scheme 3

1. CHECK DLC3 Check the DLC3. Refer to «GENERAL INFORMATION»(ref-398089-S21707799022011051600000).
2. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR Initial check Turn the power 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 power switch is turned on (IG), the passenger airbag ON/OFF indicator will indicate ON or OFF depending on the conditions listed below. Front Passenger Seat Condition Passenger Airbag ON/OFF Indicator SRS Warning Light ON Indicator OFF Indicator Vacant OFF OFF OFF Adult is seated. ON OFF OFF Child is seated. OFF ON OFF Child restraint system is set. OFF ON OFF Occupant classification system failure OFF ON ON HINT: The passenger airbag ON/OFF indicator illuminates based on the timing chart below 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 the DTCs in the airbag system first.
3. CHECK PASSENGER AIRBAG ON/OFF INDICATOR Turn the power 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: (Scheme 2)the table in previous step regarding the passenger airbag ON/OFF indicator when the power switch is turned on (IG) and approximately 6 seconds elapse.

DTC CHECK / CLEAR

1. DTC CHECK Turn the power switch off. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Occupant Detection / Trouble Codes. Check for DTCs by following the prompts on the Techstream screen. HINT: Refer to the Techstream operator's manual for further details.
2. DTC CLEAR Turn the power switch off. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Occupant Detection / Trouble Codes. Clear the DTCs by following the prompts on the Techstream screen. HINT: Refer to the Techstream operator's manual for further details.

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. Turn the power switch off. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Occupant Detection / Data List. Check the values by referring to the table below. Tester Display Measurement Item/Range Normal Condition IG Switch Power switch condition/ ON: Power switch on (IG) OFF: Power switch off ON/OFF Passenger Buckle SW Passenger side buckle switch/ Set: The seat belt is fastened Unset: The seat belt is not fastened NG: Data is not determined Set/Unset Passenger Classification Passenger classification/ AM50: Adult (more than 54 kg (119.1 lb)) is seated AF05: Adult (36 to 54 kg (79.4 to 119.1 lb)) is seated Child: Child (less than 36 kg (79.3 lb)) is seated CRS: Child restraint system is installed (less than 32 kg (70.6 lb) and passenger side buckle switch is on) OFF: Vacant AM50/AF05/Child/CRS/OFF Sensor Range Info Sensor range information/ OK: The value of a sensor is within the range NG: The value of a sensor is over the range OK FL Sensor Range Info Front left sensor range information/ OK: Sensor range is -17 to 27 kg (-37.5 to 59.5 lb) Min.: Less than -17 kg (-37.5 lb) Max.: More than 27 kg (59.5 lb) OK FR Sensor Range Info Front right sensor range information/ OK: Sensor range is -17 to 27 kg (-37.5 to 59.5 lb) Min.: Less than -17 kg (-37.5 lb) Max.: More than 27 kg (59.5 lb) OK RL Sensor Range Info Rear left sensor range information/ OK: Sensor range is -17 to 37 kg (-37.5 to 81.6 lb) Min.: Less than -17 kg (-37.5 lb) Max.: More than 37 kg (81.6 lb) OK RR Sensor Range Info Rear right sensor range information/ OK: Sensor range is -17 to 37 kg (-37.5 to 81.6 lb) Min.: Less than -17 kg (-37.5 lb) Max.: More than 37 kg (81.6 lb) OK FL Sensor Voltage Front left sensor voltage/ Min.: 0 V Max.: 19.8 V 0 to 5 V FR Sensor Voltage Front right sensor voltage/ Min.: 0 V Max.: 19.8 V 0 to 5 V RL Sensor Voltage Rear left sensor voltage/ Min.: 0 V Max.: 19.8 V 0 to 5 V RR Sensor Voltage Rear right sensor voltage/ Min.: 0 V Max.: 19.8 V 0 to 5 V FL Sensor Weight Info Front left sensor weight information/ Min.: -17 kg (-37.5 lb) Max.: 27 kg (59.5 lb) -17 to 27 kg (-37.5 to 59.5 lb) FR Sensor Weight Info Front right sensor weight information/ Min.: -17 kg (-37.5 lb) Max.: 27 kg (59.5 lb) -17 to 27 kg (-37.5 to 59.5 lb) RL Sensor Weight Info Rear left sensor weight information/ Min.: -17 kg (-37.5 lb) Max.: 37 kg (81.6 lb) -17 to 37 kg (-37.5 to 81.6 lb) RR Sensor Weight Info Rear right sensor weight information/ Min.: -17 kg (-37.5 lb) Max.: 37 kg (81.6 lb) -17 to 37 kg (-37.5 to 81.6 lb) Total Weight Information Total weight information/ Min.: -68 kg (-149.9 lb) Max.: 128 kg (282.2 lb) -68 to 128 kg (-149.9 to 282.2 lb) Number of Present DTC Number of present DTC recorded/ Min.: 0, Max.: 255 0 Number of Past DTC Number of past DTC recorded/ Min.: 0, Max.: 255 0

DIAGNOSTIC TROUBLE CODE CHART

If a trouble code is displayed during the DTC check, check the circuit listed for the code in the table below (proceed to appropriate service information listed for that circuit).

HINT

When DTC B1650/32 is detected as a result of troubleshooting for the airbag system, perform troubleshooting for the occupant classification system as shown in the chart below.

OCCUPANT CLASSIFICATION SYSTEM