Supplemental Restraint System (Diagnostics - Introduction): Other Lexus IS III

PRECAUTION [04/2013 - ]

HINT

In the airbag system, the parts listed below are collectively referred to as the airbag sensors.

1. Airbag sensor assembly (center airbag sensor)
2. Front airbag sensors
3. Door side airbag sensors
4. Side airbag sensor assemblies
5. Rear airbag sensors

The parts listed below are collectively referred to as the SRS parts.

1. Horn button assembly
2. Lower No. 1 instrument panel airbag assembly
3. Lower No. 2 instrument panel airbag assembly
4. Instrument panel passenger airbag assembly
5. Curtain shield airbag assemblies
6. Front seat airbag assemblies
7. Rear seat airbag assemblies
8. Front seat outer belt assemblies
9. Rear seat 3 point type outer belt assemblies

1. PRECAUTION FOR HANDLING SRS SYSTEM Failure to carry out service operations in the correct sequence could cause the SRS to unexpectedly deploy during servicing, possibly leading to a serious accident. Furthermore, if a mistake is made when servicing the SRS, it is possible that the SRS may fail to operate when required. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the following precautions carefully, then follow the procedures exactly as indicated in the repair manual.
2. PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL As SRS malfunctions are difficult to confirm, Diagnostic Trouble Codes (DTCs) become the most important source of information when troubleshooting. When troubleshooting the SRS, always check for DTCs before disconnecting the cable from the negative (-) battery terminal. NOTE: After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work. Refer to «PRECAUTION [04/2013 - ]»(ref-665529-S00420865962014102400000) Work must be started at least 90 seconds after the engine switch is turned off and the cable is disconnected from the negative (-) battery terminal. WARNING: The SRS is equipped with a back-up power source. If work is started within 90 seconds after disconnecting the cable from the negative (-) battery terminal, the SRS may deploy. Never use a back-up power source (battery or other) to avoid clearing the system memory. The back-up power source may inadvertently power the SRS and cause it to deploy. NOTE: When disconnecting the cable from the negative (-) battery terminal, initialize the following system(s) after the cable is reconnected. System See Procedure Variable Gear Ratio Steering System Refer to «INITIALIZATION [04/2013 - ]»(ref-665529-S01115916402014102400000) Air Conditioning System When the cable is disconnected from the negative (-) battery terminal, the memory of various systems will be cleared. Because of this, be sure to make a record of the contents memorized in each system before starting work. When work is finished, adjust each system to its previous state.
3. GENERAL PRECAUTION Use a voltmeter/ohmmeter with high impedance (minimum = 10 kohms) for troubleshooting electrical circuits. Information labels are attached to the SRS parts. Follow the instructions on the labels. Never disassemble or attempt to repair any of the SRS parts. If any of the SRS parts are dropped, or if any cracks, dents or other defects are found, replace them with new parts. Never use SRS parts from another vehicle. When replacing parts, use new parts. Do not expose any of the SRS parts directly to high temperatures or flames. If the vehicle has been involved in a minor collision where the SRS did not deploy, the SRS parts should be inspected before further use of the vehicle. Do not apply grease, detergent, oil or water to the SRS parts. If applied, immediately wipe it off with a dry cloth. When deploying or storing the SRS parts, avoid places with a high temperature (ambient temperature of 93°C (199°F) or higher for an airbag and 80°C (176°F) or higher for a pretensioner) and high humidity, and keep them away from electrical noise. Do not stack or place anything on top of the SRS parts. When disposing of the vehicle or an SRS part by itself, deploy it using SST before disposal. Deploy the SRS parts in a safe place away from electrical noise. HINT: Horn button assembly Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S00772361032014102400000) Lower No. 1 instrument panel airbag assembly Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S08412898572014102400000) Lower No. 2 instrument panel airbag assembly Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S23582797252014102400000) Instrument panel passenger airbag assembly Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S14188732032014102400000) Curtain shield airbag assemblies Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S31638725302014102400000) Front seat airbag assemblies Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S38333196082014102400000) Rear seat airbag assemblies Refer to «DISPOSAL [04/2013 - ]»(ref-665530-S38787330272014102400000) Front seat outer belt assemblies Refer to «DISPOSAL [04/2013 - ]»(ref-665531-S07064117912014102400000) Rear seat 3 point type outer belt assemblies Refer to «DISPOSAL [04/2013 - ]»(ref-665531-S20825507682014102400000) Never measure the resistance of the SRS parts. WARNING: Never measure the resistance of the SRS parts because current from the tester may cause the SRS parts to deploy.
4. PRECAUTION FOR DISPOSAL OF SRS PARTS (NOT DEPLOYED) Before performing pre-disposal deployment of any SRS parts, review and closely follow all applicable environmental and hazardous material regulations. Pre-disposal deployment may be considered hazardous material treatment. Never dispose of any SRS parts that are not deployed. Deploy the SRS parts outdoors in a safe and level place where it will not disturb nearby residents. As the SRS parts produce a loud sound when deployed, be sure to inform nearby residents before deployment. When deploying the SRS parts, always use SST and keep people at least 10 m (32.8 ft.) away. The SRS parts may be accidentally deployed by static electricity. To prevent this, be sure to touch a grounded metal surface with your bare hands to discharge any static electricity before handling the SRS parts. Do not face the airbag deployment side down when deploying an airbag.
5. PRECAUTION FOR DISPOSAL OF SRS PARTS (DEPLOYED) As the SRS parts are very hot after being deployed, allow at least 30 minutes for them to cool down sufficiently before disposal. Do not apply water etc. to any deployed SRS parts. Use gloves and safety glasses when handling any deployed SRS parts. Seal the deployed SRS parts in a thick clear plastic bag when disposing them. Always wash your hands with water after disposing of deployed SRS parts.
6. PRECAUTION FOR HORN BUTTON ASSEMBLY, LOWER NO. 1 INSTRUMENT PANEL AIRBAG ASSEMBLY, LOWER NO. 2 INSTRUMENT PANEL AIRBAG ASSEMBLY, INSTRUMENT PANEL PASSENGER AIRBAG ASSEMBLY, CURTAIN SHIELD AIRBAG ASSEMBLY, FRONT SEAT AIRBAG ASSEMBLY AND REAR SEAT AIRBAG ASSEMBLY Keep the airbag deployment side facing upward even when the airbag is temporarily removed during service. WARNING: Always place a removed or new airbag with the deployment surface facing upward. Placing the airbag with the deployment surface facing downward could cause a serious accident if the airbag deploys.
7. PRECAUTION FOR FRONT SEAT OUTER BELT ASSEMBLY (PRETENSIONER) AND REAR SEAT 3 POINT TYPE OUTER BELT ASSEMBLY (PRETENSIONER) Do not touch the area around the retractor even when the pretensioner is temporarily removed during service. WARNING: If the retractor unexpectedly operates and the belt is retracted during an operation, it could cause a serious accident.
8. PRECAUTION FOR SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY Do not replace the spiral cable with sensor sub-assembly with the battery connected and the engine switch on (IG). Do not rotate the spiral cable with sensor sub-assembly without the steering wheel assembly with the battery connected and the engine switch on (IG). Ensure that the steering wheel assembly is installed and aligned straight when inspecting the steering sensor. When rotating the spiral cable with sensor sub-assembly, make sure to push on the interlock to release the interlock mechanism. Be sure that the spiral cable with sensor sub-assembly is in the neutral position during installation and when removing and installing the steering wheel assembly. Refer to «PROCEDURE - Step 4»(ref-665530-S09770702912014102400000) WARNING: If the steering wheel assembly is turned without the spiral cable installed in the neutral position, the cable may break.
9. PRECAUTION FOR AIRBAG SENSORS Perform a diagnostic system check. Refer to «DTC CHECK / CLEAR [04/2013 - ]»(ref-665792-S03803756002014102400000) When the SRS parts are deployed (including when only an airbag or pretensioner is deployed) due to a collision, be sure to replace all sensors in the damaged areas (anywhere in need of repair) and airbag sensor assembly (center airbag sensor). Visually check the airbag sensors in undamaged areas for defects. The defects are as follows: Cracks on the sensor housing Dents on the sensor housing Chips on the sensor housing Cracks or other damage to the connector Damage to the serial number OK No defects are found. If any defects are found or an airbag sensor has detected a major collision, replace the airbag sensor with a new one.
10. PRECAUTION FOR WIRE HARNESS AND CONNECTOR All wire harnesses except unexposed harnesses in the engine room are colored yellow. As special connectors are used, be careful when handling them.
11. WHEN SERVICING DAMAGED VEHICLE Before using an electric welder on the vehicle, remove any SRS parts around the area being repaired. WARNING: Make sure to remove any SRS parts as necessary to prevent them from accidentally deploying. Before repairs, remove the airbag sensor assemblies if impacts are likely to be applied to the sensor during repairs. Never expose an airbag sensor directly to high temperatures. As the SRS parts are very hot after being deployed, ensure that all wire harnesses and connectors around deployed SRS parts are not damaged.
12. CONDITIONS WHEN INSPECTION OF SRS PARTS IS NECESSARY When the vehicle is damaged in a collision even when the SRS parts are not deployed. When SRS system DTCs are output.

Scheme 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

COMMUNICATION TABLE

Scheme 179

Scheme 180

Scheme 181

1. GENERAL Deceleration sensors used for the airbag system are installed on various parts on the vehicle and calculate the deceleration rate of each part during a collision. Depending on the situation, the airbag sensor assembly sends a deployment signal to each airbag and pretensioner based on the information from each sensor.
2. DEPLOYMENT CONDITION FRONTAL COLLISION Frontal collision signals are produced based on the information from the airbag sensor assembly and front airbag sensors. HINT: *1: In case of a frontal collision, the SRS ignition signal may be output after receiving an ON signal from the deceleration sensor built in the airbag sensor assembly even without a signal from the front airbag sensors. Frontal collision signals are used to deploy the airbags and pretensioners in the illustration. HINT: The occupant classification system restricts the deployment of the instrument panel passenger airbag assembly and lower No. 2 instrument panel airbag assembly. Refer to «FAIL-SAFE CHART [04/2013 - ]»(ref-665567-S25866400732014102400000) SIDE COLLISION (Pattern 1) Side collision (Pattern 1) signals are produced based on the information from the airbag sensor assembly, side airbag sensor assembly and door side airbag sensor. Side collision (Pattern 1) signals are used to deploy the airbags and pretensioner in the illustration. SIDE COLLISION (Pattern 2) Side collision (Pattern 2) signals are produced based on the information from the airbag sensor assembly and rear airbag sensor. Side collision (Pattern 2) signals are used to deploy the airbags in the illustration.

CAUTION / NOTICE / HINT

HINT

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

PROCEDURE

1. VEHICLE BROUGHT TO WORKSHOP Result Proceed to NEXT Result: 1 NEXT See step 2
2. CUSTOMER PROBLEM ANALYSIS Confirm problem symptoms. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING [04/2013 - ]»(ref-665529-S21853141262014102400000) Result Proceed to NEXT Result: 1 NEXT See step 3
3. CHECK CAN COMMUNICATION SYSTEM* Using the Techstream, check if the CAN communication system is functioning normally. OK CAN communication system is functioning normally. HINT: Refer to CAN Bus Check for the CAN communication system Refer to «DIAGNOSIS SYSTEM [04/2013 - ]»(ref-665810-S14264089842014102400000) The airbag sensor assembly is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there are no malfunctions in the CAN communication system. Result Proceed to OK NG Result: 2 NG GO TO CAN COMMUNICATION SYSTEM. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING [04/2013 - ]»(ref-665785-S15342612202014102400000) Result: 1 OK See step 4
4. SRS WARNING LIGHT CHECK Proceed to Diagnosis System. Refer to «DIAGNOSIS SYSTEM [04/2013 - ]»(ref-665792-S33736397992014102400000) Result Proceed to NEXT Result: 1 NEXT See step 5
5. CHECK FOR DTC* Proceed to DTC Check / Clear. Refer to «DTC CHECK / CLEAR [04/2013 - ]»(ref-665792-S03803756002014102400000) Body Electrical > SRS Airbag > Trouble Codes OK DTCs are not output. Result Proceed to OK NG Result: 2 NG See step 12 Result: 1 OK See step 6
6. SYMPTOM SIMULATION Proceed to How to Proceed with Troubleshooting. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING [04/2013 - ]»(ref-665529-S21853141262014102400000) Result Proceed to NEXT Result: 1 NEXT See step 7
7. PROBLEM SYMPTOMS TABLE Proceed to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE [04/2013 - ]»(ref-665792-S11364000012014102400000) Result Proceed to NEXT Result: 1 NEXT See step 8
8. CIRCUIT INSPECTION* Result Proceed to NEXT Result: 1 NEXT See step 9
9. IDENTIFICATION OF PROBLEM Result Proceed to NEXT Result: 1 NEXT See step 10
10. REPAIR OR REPLACEMENT Result Proceed to NEXT Result: 1 NEXT See step 11
11. CONFIRMATION TEST Result Proceed to NEXT Result: 1 NEXT END
12. DIAGNOSTIC TROUBLE CODE CHART Proceed to Diagnostic Trouble Code Chart. Refer to «DIAGNOSTIC TROUBLE CODE CHART [04/2013 - ]»(ref-665792-S06886873772014102400000) Result Proceed to NEXT Result: 1 NEXT See step 13
13. CIRCUIT INSPECTION* Result Proceed to NEXT Result: 1 NEXT See step 14
14. IDENTIFICATION OF PROBLEM Result Proceed to NEXT Result: 1 NEXT See step 15
15. REPAIR OR REPLACEMENT Result Proceed to NEXT Result: 1 NEXT See step 16
16. CONFIRMATION TEST Result Proceed to NEXT Result: 1 NEXT END

CHECK MODE PROCEDURE [04/2013 - ]

1. CHECK MODE (SIGNAL CHECK): DTC CHECK Turn the engine switch off. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / SRS Airbag / Utility / Signal Check, and proceed with checking using the Techstream. Body Electrical > SRS Airbag > Utility Tester Display Signal Check NOTE: Select Signal Check on the Techstream to clear the output DTCs (both current and history). HINT: DTCs can be detected more sensitively in check mode than in normal diagnosis mode. Perform check mode inspection when a malfunction in a squib circuit is suspected even after the normal system code is output through normal diagnosis mode inspection.