Supplemental Restraint System (Diagnostics - Introduction): Diagnosis Lexus HS I

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use the following procedure to troubleshoot the airbag 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. CHECK CAN COMMUNICATION SYSTEM* Use the Techstream to check if the CAN communication system is functioning normally. HINT: Refer to Bus Check for the CAN communication system. Refer to «DIAGNOSIS SYSTEM»(ref-398235-S15853483682011051600000) . The center airbag sensor assembly is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system. Result Result Proceed to CAN communication DTC is not output. A CAN communication DTC is output. B B --> INSPECT CAN COMMUNICATION CIRCUIT. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-398235-S17886579092011051600000) A: Go to next step
4. SRS WARNING LIGHT CHECK Proceed to Diagnosis System. Refer to «DIAGNOSIS SYSTEM»(ref-398246-S08284640642011051600000) . NEXT: Go to next step
5. CHECK FOR DTC* Proceed to DTC Check / Clear. Refer to «DTC CHECK / CLEAR»(ref-398246-S01125415292011051600000) . Result Result Proceed to DTC is output. A DTC is not output. B B --> Go to step 7 . A: Go to next step
6. DIAGNOSTIC TROUBLE CODE CHART Proceed to Diagnostic Trouble Code Chart. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-398246-S23494487152011051600000) . NEXT --> Go to step 9 .
7. SYMPTOM SIMULATION Proceed to Diagnosis System. Refer to «DIAGNOSIS SYSTEM»(ref-398246-S08284640642011051600000) . NEXT: Go to next step
8. PROBLEM SYMPTOMS TABLE Proceed to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE»(ref-398246-S04288610152011051600000) . NEXT: Go to next step
9. CIRCUIT INSPECTION* NEXT: Go to next step
10. IDENTIFICATION OF PROBLEM NEXT: Go to next step
11. REPAIR OR REPLACEMENT NEXT: Go to next step
12. 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.

AIRBAG SYSTEM

Scheme 157

1. CENTER AIRBAG SENSOR ASSEMBLY Terminal No. Terminal Symbol Destination F34-1 P2+ Front passenger airbag assembly (Front passenger side squib 2nd step) F34-2 P2- Front passenger airbag assembly (Front passenger side squib 2nd step) F34-3 P- Front passenger airbag assembly (Front passenger side squib) F34-4 P+ Front passenger airbag assembly (Front passenger side squib) F34-5 D+ Steering pad (Driver side squib) F34-6 D- Steering pad (Driver side squib) F34-7 D2- Steering pad (Driver side squib 2nd step) F34-8 D2+ Steering pad (Driver side squib 2nd step) F34-9 DK+ Driver side knee airbag assembly (Driver side knee airbag squib) F34-10 DK- Driver side knee airbag assembly (Driver side knee airbag squib) F34-13 CANH CAN communication line F34-14 GSW2 Hybrid vehicle control ECU F34-17 P-AB Telltale light assembly (Passenger airbag ON/OFF indicator) F34-18 GSW Main body ECU F34-19 PK+ Front passenger side knee airbag assembly (Front passenger side knee airbag squib) F34-20 PK- Front passenger side knee airbag assembly (Front passenger side knee airbag squib) F34-21 IG2 IGN fuse F34-22 CANL CAN communication line F34-23 PAON Telltale light assembly (Passenger airbag ON/OFF indicator) F34-24 GSW3 Telematics Transceiver F34-25 E1 Ground F34-26 E2 Ground F34-27 -SR Front airbag sensor RH F34-28 -SL Front airbag sensor LH F34-29 +SR Front airbag sensor RH F34-30 +SL Front airbag sensor LH L1-1 SFL+ Front seat side airbag assembly LH (Front side squib LH) L1-2 SFL- Front seat side airbag assembly LH (Front side squib LH) L1-3 ICL- Curtain shield airbag assembly LH (Curtain shield squib LH) L1-4 ICL+ Curtain shield airbag assembly LH (Curtain shield squib LH) L1-5 PL+ Front seat outer belt assembly LH (Front pretensioner squib LH) L1-6 PL- Front seat outer belt assembly LH (Front pretensioner squib LH) L1-7 PLR- Rear seat outer belt assembly LH (Rear pretensioner squib LH) L1-8 PLR+ Rear seat outer belt assembly LH (Rear pretensioner squib LH) L1-9 LSP+ Seat position sensor L1-10 LBE+ Front seat inner belt assembly LH (Seat belt buckle switch LH) L1-15 RL- Rear seat side airbag assembly LH (Rear side squib LH) L1-16 RL+ Rear seat side airbag assembly LH (Rear side squib LH) L1-17 LSP- Seat position sensor L1-18 LBE- Front seat inner belt assembly LH (Seat belt buckle switch LH) L1-23 BBL- Side airbag sensor LH L1-24 BBL+ Side airbag sensor LH M1-1 PRR+ Rear seat outer belt assembly RH (Rear pretensioner squib RH) M1-2 PRR- Rear seat outer belt assembly RH (Rear pretensioner squib RH) M1-3 PR- Front seat outer belt assembly RH (Front pretensioner squib RH) M1-4 PR+ Front seat outer belt assembly RH (Front pretensioner squib RH) M1-5 ICR+ Curtain shield airbag assembly RH (Curtain shield squib RH) M1-6 ICR- Curtain shield airbag assembly RH (Curtain shield squib RH) M1-7 SFR- Front seat side airbag assembly RH (Front side squib RH) M1-8 SFR+ Front seat side airbag assembly RH (Front side squib RH) M1-9 RR+ Rear seat side airbag assembly RH (Rear side squib RH) M1-10 RR- Rear seat side airbag assembly RH (Rear side squib RH) M1-16 FSR+ Occupant classification ECU M1-17 BBR+ Side airbag sensor RH M1-18 BBR- Side airbag sensor RH M1-24 FSR- Occupant classification ECU

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

Scheme 167

Scheme 168

Scheme 169

Scheme 170

Scheme 171

1. CHECK DLC3 Check the DLC3. Refer to «GENERAL INFORMATION»(ref-398089-S21707799022011051600000).
2. FUNCTION OF SRS WARNING LIGHT Primary check Turn the power switch off. Wait for at least 2 seconds, then turn the power switch on (IG). The SRS warning light comes on for approximately 6 seconds and the diagnosis of the airbag system (including the seat belt pretensioners) is performed. HINT: If malfunctions are detected during the primary check, the SRS warning light remains on even after the primary check period of approximately 6 seconds. Constant check After the primary check, the center airbag sensor assembly constantly monitors the airbag system for malfunctions. HINT: If malfunctions are detected during the constant check, the center airbag sensor assembly functions as follows: The SRS warning light comes on. The SRS warning light goes off, and then comes on. This indicates a source voltage drop. The SRS warning light goes off 10 seconds after the source voltage returns to normal. Review When the airbag system is normal: The SRS warning light comes on only during the primary check period of approximately 6 seconds after the power switch is turned on (IG). When the airbag system is malfunctioning: The SRS warning light remains on even after the primary check period. The SRS warning light goes off after the primary check, but comes on again during the constant check. The SRS warning light does not come on when turning the power switch from off to on (IG). HINT: The center airbag sensor assembly functions to keep the SRS warning light on if the airbag has been deployed.
3. SRS WARNING LIGHT CHECK Turn the power switch on (IG), and check that the SRS warning light comes on for approximately 6 seconds (primary check). Check that the SRS warning light goes off approximately 6 seconds after the power switch is turned on (IG) (constant check). HINT: When any of the following symptoms occur, refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE»(ref-398246-S04288610152011051600000). The SRS warning light comes on occasionally after the primary check period. The SRS warning light comes on, but a DTC is not output. The power switch is turned from off to on (IG), but the SRS warning light does not come on.
4. FUNCTION OF PASSENGER AIRBAG ON/OFF INDICATOR Initial check Turn the power switch 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 power switch is turned on (IG), the passenger airbag ON/OFF indicator will indicate ON/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 Front passenger occupant classification 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. Then troubleshoot the occupant classification system if DTC B1650/32 is detected, and troubleshoot the passenger airbag ON/OFF indicator if DTC B1660/43 is detected.
5. PASSENGER AIRBAG ON/OFF INDICATOR CHECK 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: Refer to the table in step 4 regarding the passenger airbag ON/OFF indicator when the power switch is turned on (IG) and approximately 6 seconds elapse.
6. FUNCTION OF SRS CONNECTORS The SRS connectors are located as shown in the illustration. Connector Type Application Terminal Twin-lock Mechanism Connectors 2, 4, 6, 9, 10, 17, 18, 22, 24, 29, 30 Half Connection Prevention Mechanism Connectors 6, 10, 18, 30 Activation Prevention Mechanism Connectors 2, 4, 5, 7, 9, 11, 13, 15, 29, 31, 33, 35 Connector Lock Mechanism (1) Connectors 8, 12, 14, 16, 32, 34, 36 Connector Position Assurance Mechanism Connector 20 Connector Lock Mechanism (2) Connector A Improper Connection Prevention Lock Mechanism Connector A Terminal twin-lock mechanism This mechanism is designed to increase the ability of the terminal to remain connected and prevent it from accidentally being disconnected. The connector has a two-piece construction consisting of the housing and spacer to securely lock the terminal using both the lance (primary lock) and spacer (secondary lock). Half connection prevention mechanism This mechanism is designed to prevent the connector from being connected only halfway. If the connector is not completely connected, the connector is disconnected due to the spring force so that no continuity exists. Activation prevention mechanism The activation prevention mechanism is designed to create a short circuit automatically between the positive (+) and negative (-) terminals of an airbag power source connector when disconnected. The short spring plate contained in the connector creates a closed circuit on the airbag side (no potential difference can occur between both terminals), preventing accidental airbag deployment when servicing. Connector lock mechanism (1) This mechanism is designed to prevent the connector from accidentally being disconnected. Locking the connector lock button engages the locking button claw to the groove on the other side connector to connect the connector securely. Connector Position Assurance (CPA) mechanism This mechanism is designed to detect when the connector is connected only halfway. The CPA and female connector slide to the male connector side at the same time and the primary lock is completed when the female connector is engaged with the male connector. From this point, only the CPA slides to the male connector side and secondary lock is completed when the CPA retainer is engaged with the female connector. When the CPA and female connector ends are aligned, they are completely engaged. Connector lock mechanism (2) This mechanism is designed to prevent the connector from accidentally being disconnected. Sliding the connector all the way into the holder and locking the lance completes the primary lock. Engaging the retainer to the holder as shown in the illustration completes the secondary lock, preventing the connector from accidentally being disconnected. Improper connection prevention lock mechanism This mechanism is designed to prevent the connector from being connected only halfway. When the holder is connected to the center airbag sensor assembly, the unlock rib unlocks the temporarily hold lock, allowing the lever to be pushed in by rotating around the A axis. Locking the lever to the holder locks the holder securely.
7. ACTIVATION PREVENTION MECHANISM Function of activation prevention mechanism An activation prevention mechanism is built into the connector (on the center airbag sensor assembly side) of the airbag system squib circuit to prevent accidental airbag activation. This mechanism closes the circuit when the connector is disconnected by bringing the short spring into contact with the terminals and insulating the circuit from external power sources to prevent accidental airbag activation. Releasing of activation prevention mechanism To release the activation prevention mechanism, insert a piece of paper with the same thickness as the male terminal (approximately 0.5 mm (0.0197 in.)) between the terminals and short spring to break the connection. (Scheme 171)the following illustrations concerning connectors utilizing the activation prevention mechanism and its release method. WARNING: Never release the activation prevention mechanism on the squib connector even when inspecting with the squib disconnected. NOTE: Do not release the activation prevention mechanism unless specially directed by the troubleshooting procedure. To prevent the terminal and short spring from being damaged, always use a piece of paper with the same thickness as the male terminal.

Scheme 172

Scheme 173

Scheme 174

1. DTC CHECK (USING SST CHECK WIRE) Check for DTCs (Present trouble codes). Turn the power switch on (IG), and wait for approximately 60 seconds. Using SST, connect terminals TC and CG of the DLC3. SST: 09843-18040 NOTE: Connect the terminals to the correct positions to avoid a malfunction. Check for DTCs (History trouble codes). Using SST, connect terminals TC and CG of the DLC3. SST: 09843-18040 NOTE: Connect the terminals to the correct positions to avoid a malfunction. Turn the power switch on (IG), and wait for approximately 60 seconds. Read the DTCs. Read the blinking patterns of the DTCs. As examples, the blinking patterns for the normal system code and trouble codes 11 and 31 are shown in the illustration. Normal system code indication (without history trouble code) The light blinks twice per second. Normal system code indication (with history trouble code) When the history trouble code is stored in the center airbag sensor assembly, the light blinks only once per second. Trouble code indication The first blinks indicate the first DTC. The second blinks occur after a 1.5-second pause. If there is more than 1 code, there will be a 2.5-second pause between each code. After all codes are shown, there will be a 4.0-second pause, and then all codes will be repeated. HINT: If 2 or more malfunctions are found, the indication begins with the smaller-numbered code. If DTCs are indicated without connecting the terminals, proceed to TC and CG Terminal Circuit. Refer to «TC and CG Terminal Circuit»(ref-398337-S30445189702011051600000) .
2. DTC CLEAR (USING SST CHECK WIRE) Clear the DTCs. When the power switch is turned off, the DTCs are cleared. HINT: Depending on the DTC, the code may not be cleared by turning off the power switch. In this case, proceed to the next procedure. Using SST, connect terminals TC and CG of the DLC3, and then turn the power switch on (IG). SST: 09843-18040 Disconnect terminal TC of the DLC3 within 3 to 10 seconds after the DTCs are output, and check if the SRS warning light comes on after 3 seconds. Within 2 to 4 seconds after the SRS warning light comes on, connect terminals TC and CG of the DLC3. The SRS warning light should go off within 2 to 4 seconds after connecting terminals TC and CG of the DLC3. Then, disconnect terminal TC within 2 to 4 seconds after the SRS warning light goes off. The SRS warning light comes on again within 2 to 4 seconds after disconnecting terminal TC. Then, reconnect terminals TC and CG within 2 to 4 seconds after the SRS warning light comes on. Check if the SRS warning light goes off within 2 to 4 seconds after connecting terminals TC and CG of the DLC3. Also check if the normal system code is output within 1 second after the SRS warning light goes off. If DTCs are not cleared, repeat this procedure until the codes are cleared.
3. DTC CHECK (USING TECHSTREAM) 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 / SRS Airbag / Trouble Codes. Check for DTCs by following the prompts on the Techstream screen. HINT: Refer to the Techstream operator's manual for further details.
4. DTC CLEAR (USING TECHSTREAM) 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 / SRS Airbag / 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

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.

1. DATA LIST FOR CENTER AIRBAG SENSOR ASSEMBLY 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 / SRS Airbag / Data List. Check the values by referring to the table below. SRS AIRBAG Tester Display Measurement Item/Range Normal Condition Driver Seat Position Driver Seat Position/ Forward: Seat position is forward Bkward: Seat position is backward Fail: Failure detected Forward/Bkward Passenger Classification Passenger Classification/ NG: Date is not determined OFF: Vacant Child: Child (less than 36 kg (79.4 lb)) is seated AF05: Adult (36 to 54 kg (79.4 to 119.1 lb)) is seated AM50: Adult (more than 54 kg (119.1 lb)) is seated Fail: A failure is detected OFF/Child/AF05/AM50 Left Side Buckle SW LH Side Buckle SW/ Unset: The seat belt is not fastened Set: The seat belt is fastened NG: Data is not determined Unset/Set Right Side Buckle SW RH Side Buckle SW/ Unset: The seat belt is not fastened Set: The seat belt is fastened NG: Data is not determined Unset/Set Display Type Information Display Type Information/ LR: The display is indicated by LH/RH DP: The display is indicated by Driver/Passenger LR Number of Past DTC Number of Past DTC/ 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 (refer to the appropriate service information).

HINT

1. When the SRS warning light remains on and the DTC output is the normal system code, a voltage source drop is likely to occur. This malfunction is not stored in the memory by the center airbag sensor assembly. If the power source voltage returns to normal, the SRS warning light will automatically go off.
2. When 2 or more codes are indicated, the code with the lower number appears first.
3. If a code is not listed on the display chart, the center airbag sensor assembly may have failed.
4. In the case of any malfunction concerning an open circuit, short to ground, or short to B+ due to a squib, other trouble codes may not be detected. In this case, repair the malfunction currently indicated and then perform malfunction diagnosis again.
5. Mark in the check mode column: *1: DTC does not correspond to check mode. *2: DTC corresponds to check mode.

AIRBAG SYSTEM