Occupant Classification System (diagnostics - Introduction) Toyota Prius C I

PRECAUTION

1. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE AUXILIARY BATTERY TERMINAL NOTE: When disconnecting the cable from the negative (-) auxiliary battery terminal, initialize the following system(s) after the cable is reconnected: System See Procedure Power Door Lock Control System Refer to «INITIALIZATION»(/toyota/prius-c/i-2011-2015/remont/door-locks-anti-theft-systems/#power-door-lock-control-system-diagnostics-symptom-tests__initialization)
2. IGNITION SWITCH EXPRESSIONS The type of ignition switch used on this model differs according to the specification of the vehicle. The expressions listed in the table below are used in this information. Expression Ignition Switch (Position) Power Switch (Condition) Ignition Switch off LOCK Off (Lock) Ignition Switch ACC ACC On (ACC) Ignition Switch ON (IG) ON (IG) On (IG) Ignition Switch ON (READY) ON (READY) On (Ready)
3. GENERAL PRECAUTION Perform zero point calibration and sensitivity check if any of the following conditions occur: The occupant detection ECU is replaced. Accessories (seatback tray and seat cover, etc.) are installed. The front passenger seat is removed from the vehicle. One of the bolts that is used to install the front passenger seat is removed and reinstalled. The vehicle is brought to the workshop for repair due to an accident or a collision.

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SYSTEM DESCRIPTION

1. GENERAL In the occupant classification system, the occupant detection ECU calculates the weight of the occupant based on signals from the occupant classification sensors. This system judges whether the front passenger seat is occupied by an adult, child or child restraint system or not based on the calculated weight and the passenger side buckle switch state, and then it restricts the operation of the front passenger airbag, SRS seat cushion airbag RH and front seat belt pretensioner RH based on the result. This system is mainly comprised of 2 occupant classification sensors that detect the load on the front passenger seat. The occupant detection ECU controls the system, and the passenger airbag ON/OFF indicator indicates the ON/OFF condition of the front passenger airbag, SRS seat cushion airbag RH and front seat belt pretensioner RH.

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»(/toyota/prius-c/i-2011-2015/remont/hoistjack/#introduction) . NEXT: Go to next step
3. PASSENGER AIRBAG ON/OFF INDICATOR CHECK Proceed to Diagnosis System. Refer to «DIAGNOSIS SYSTEM»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction) . NEXT: Go to next step
4. DTC CHECK (Present and History DTCs)* Proceed to DTC Check / Clear. Refer to «DTC CHECK / CLEAR»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__dtc-check-clear) . Result Result Proceed to DTC is output. A DTC is not output. B B --> GO TO PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__problem-symptoms-table) A: Go to next step
5. DTC CHART Proceed to Diagnostic Trouble Code Chart. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__diagnostic-trouble-code-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)* Proceed to DTC Check / Clear. Refer to «DTC CHECK / CLEAR»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__dtc-check-clear) . NEXT: Go to next step
9. DTC CHECK* Proceed to DTC Check / Clear. Refer to «DTC CHECK / CLEAR»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__dtc-check-clear) . 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»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__diagnostic-trouble-code-chart) 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»(/toyota/prius-c/i-2011-2015/remont/airbag/#occupant-classification-system-diagnostics-introduction__diagnostic-trouble-code-chart) A: Go to next step
11. CONFIRMATION TEST NEXT --> END

INITIALIZATION

Note. Make sure that the front passenger seat is not occupied before performing the operation.

HINT

Perform zero point calibration and sensitivity check if any of the following conditions occur

1. The occupant detection ECU is replaced.
2. Accessories (seatback tray and seat cover, etc.) are installed.
3. The front passenger seat is removed from the vehicle.
4. One of the bolts that install the front passenger seat is removed.
5. The vehicle is brought to the workshop for repair due to an accident or a collision.

1. ZERO POINT CALIBRATION AND SENSITIVITY CHECK Zero point calibration and sensitivity check procedure HINT: Make sure that zero point calibration has finished normally, and then perform the sensitivity check. Check that both of the following conditions are met: The vehicle is parked on a level surface. No objects are placed on the front passenger seat. Adjust the seat position according to the table below. Adjustment Item Position Slide Direction Foremost position Headrest Height Lowest position Recline Angle Follow the prompts on the Techstream screen. Turn the ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to ON (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Occupant Detection / Utility / Zero Point Calibration & Sensitivity Check. Perform zero point calibration and sensitivity check by following the prompts on the Techstream screen. OK "Zero Point Calibration is complete." and "Sensitivity Check is complete." are displayed. HINT: Refer to the Techstream operator's manual for further details. If zero point calibration does not complete, replace the separate type front seat cushion spring assembly. When performing sensitivity check, use a solid metal weight (the check result may not appear properly if a liquid weight is used). When performing sensitivity check, place the weight on the seat cushion so that it contacts the seatback. If sensitivity deviates from the specified range, retighten the bolts of the front passenger seat without deforming the seat rail. After performing this procedure, if sensitivity is not within the specified range, replace the separate type front seat cushion spring assembly.

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

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1. OCCUPANT DETECTION ECU Terminal No. (Symbol) Wiring Color Terminal Description Condition Specification Y3-1 (+B) - Y3-3 (GND) W - W-B Auxiliary battery Ignition switch off 11 to 14 V Y3-2 (DIA) - Y3-3 (GND) GR - W-B Diagnosis (DLC3) Ignition switch ON (IG), Techstream not connected to DLC3 Below 1 V Y3-3 (GND) - Body ground W-B - Body ground Ground Always Below 1 V Y3-4 (FSR-) - Y3-3 (GND) LG - W-B Airbag sensor assembly communication line Always Below 1 V Y3-5 (BGND) - Y3-3 (GND) P - W-B Passenger side buckle switch ground line Always Below 1 V Y3-6 (IG) - Y3-3 (GND) B - W-B Power source Ignition switch ON (IG) 11 to 14 V Y3-7 (FSR+) - Y3-4 (FSR-) L - LG Airbag sensor assembly communication line Ignition switch ON (IG) Pulse generation Y3-8 (BSW) - Y3-5 (BGND) G - P Passenger side buckle switch line Always Pulse generation Y2-1 (SVC3) - Y2-5 (SGD3) GR - W Rear occupant classification sensor LH power supply line Ignition switch ON (IG) 4.9 to 5.1 V Y2-2 (SVC4) - Y2-6 (SGD4) V - BR Rear occupant classification sensor RH power supply line Ignition switch ON (IG) 4.9 to 5.1 V Y2-3 (SIG3) - Y2-5 (SGD3) SB - W Rear occupant classification sensor LH signal line Ignition switch ON (IG) Pulse generation Y2-4 (SIG4) - Y2-6 (SGD4) B - BR Rear occupant classification sensor RH signal line Ignition switch ON (IG) Pulse generation Y2-5 (SGD3) - Y3-3 (GND) W - W-B Rear occupant classification sensor LH ground line Always Below 1 V Y2-6 (SGD4) - Y3-3 (GND) BR - W-B Rear occupant classification sensor RH ground line Always Below 1 V

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1. CHECK DLC3 Check the DLC3. Refer to «GENERAL INFORMATION»(/toyota/prius-c/i-2011-2015/remont/hoistjack/#introduction) .
2. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR Initial check Turn the ignition switch to ON (IG). The passenger airbag ON/OFF indicator comes on for approximately 4 seconds, then goes off for approximately 2 seconds. Approximately 6 seconds after the ignition switch is turned to ON (IG), the passenger airbag ON/OFF indicator will indicate ON/OFF depending on the conditions listed below. INDICATOR OPERATION Front Passenger Seat Condition Passenger Airbag ON/OFF Indicator SRS Warning Light ON Indicator OFF Indicator Vacant OFF ON OFF Adult is seated. ON OFF OFF Child is seated. OFF ON OFF Child restraint system is installed. 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 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 ignition switch to 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 indicator operation table in the preceding step regarding the passenger airbag ON/OFF indicator when the ignition switch is turned to ON (IG) and approximately 6 seconds elapse.

DTC CHECK / CLEAR

1. DTC CHECK Turn the ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to 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 ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to 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.

FAIL-SAFE CHART

1. FAIL SAFE FUNCTION The following chart shows the status of the controls when the system is normal and malfunctioning. 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 ignition switch is turned to ON (IG), the passenger airbag ON/OFF indicator will indicate ON or OFF depending on the conditions listed below. Condition ON Indicator OFF Indicator Front Passenger Airbag Front Seat Side Airbag RH SRS Seat Cushion Airbag RH Curtain Shield Airbag RH Front Seat Belt Pretensioner RH Adult is seated. ON OFF o o o* o o Child is seated. OFF ON X o X o o Child restraint system is installed. OFF ON X o X o o Vacant OFF ON X o X o o Failure OFF ON X o X o o o: Deployable X: Not deployable *: Not be deployed when the front passenger seat belt has been unfastened.

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 ignition switch off. Connect the Techstream to the DLC3. Turn the ignition switch to 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. OCCUPANT DETECTION Tester Display Measurement Item/Range Normal Condition Diagnostic Note IG Switch ignition switch condition/ ON: Ignition switch ON (IG) OFF: Ignition 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 is seated. (More than 39 kg (86.0 lb) is detected.) AF05: Adult is seated. (17 to 39 kg (37.5 to 86.0 lb) is detected.) Child: Child is seated. (Less than 17 kg (37.5 lb) is detected.) CRS: Child restraint system is installed. (Less than 16 kg (35.3 lb) is detected and the passenger side buckle switch is on.) OFF: Vacant AM50/AF05/Child/CRS/OFF The weight detected by the system is not always consistent with actual occupant's weight. 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 - RL Sensor Range Info Rear left sensor range information/ OK: Sensor range is -10.00 to 30.00 kg (-22.05 to 66.13 lb) Min.: Less than -10.00 kg (-22.05 lb) Max.: More than 30.00 kg (66.13 lb) OK - RR Sensor Range Info Rear right sensor range information/ OK: Sensor range is -10.00 to 30.00 kg (-22.05 to 66.13 lb) Min.: Less than -10.00 kg (-22.05 lb) Max.: More than 30.00 kg (66.13 lb) OK - RL Sensor Voltage Rear left sensor voltage/ Min.: 0.000 V Max.: 19.800 V 0.000 to 5.000 V - RR Sensor Voltage Rear right sensor voltage/ Min.: 0.000 V Max.: 19.800 V 0.000 to 5.000 V - RL Sensor Weight Info Rear left sensor weight information/ Min.: -10.00 kg (-22.05 lb) Max.: 30.00 kg (66.13 lb) -10.00 to 30.00 kg (-22.05 to 66.13 lb) - RR Sensor Weight Info Rear right sensor weight information/ Min.: -10.00 kg (-22.05 lb) Max.: 30.00 kg (66.13 lb) -10.00 to 30.00 kg (-22.05 to 66.13 lb) - Total Weight Information Total weight information/ Min.: -40.00 kg (-88.19 lb) Max.: 100.00 kg (220.46 lb) -40.00 to 100.00 kg (-88.19 to 220.46 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 information listed for that DTC).

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

See also:
• INITIALIZATION
• HOW TO PROCEED WITH TROUBLESHOOTING
• Trouble in Passenger Airbag ON/OFF Indicator
• DIAGNOSIS SYSTEM
• DTC CHECK / CLEAR
• PROBLEM SYMPTOMS TABLE
• DIAGNOSTIC TROUBLE CODE CHART