Pre-Collision (Diagnostics - Introduction): Diagnosis Lexus CT I

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use the following procedure to troubleshoot the pre-collision system.
2. The Techstream should be used in steps 3, 4 and 6.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. INSPECT AUXILIARY BATTERY VOLTAGE Measure the auxiliary battery voltage with the power switch off. Standard voltage 11 to 14 V If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step. NG --> CHARGE OR REPLACE BATTERY OK: Go to next step
3. CHECK CAN COMMUNICATION SYSTEM Use the Techstream to check if the CAN communication system is functioning normally. Refer to «DTC CHECK / CLEAR»(ref-568837-S01373230312013072300000) . Result DTC Condition Proceed to CAN DTC is not output A CAN DTC is output B B --> GO TO CAN COMMUNICATION SYSTEM. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-568746-S19329885762013072300000) A: Go to next step
4. CHECK FOR DTC Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568837-S01373230312013072300000) . Record the DTCs. Clear the DTCs. Recheck for DTCs. Attempt to duplicate the malfunction and check if the DTCs are output again. Refer to «DTC CHECK / CLEAR»(ref-568837-S01373230312013072300000) . Result DTC Condition Proceed to DTC is not output A DTC is output B No DTC is output, and malfunction cannot be duplicated or checked C B --> GO TO DTC CHART. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-568837-S00457208902013072300000) C --> GO TO SYMPTOM SIMULATION. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-568589-S05901111982013072300000) A: Go to next step
5. PROBLEM SYMPTOMS TABLE Refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE»(ref-568837-S30276286932013072300000) . 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 7 A: Go to next step
6. OVERALL ANALYSIS AND TROUBLESHOOTING Data List / Active Test. Refer to «DATA LIST / ACTIVE TEST»(ref-568837-S29041207332013072300000) Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-568837-S06327130862013072300000) 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.

PRE-COLLISION SYSTEM

Scheme 290

Scheme 291

Scheme 292

Scheme 293

Scheme 294

Scheme 295

1. CHECK SEAT BELT CONTROL ECU Disconnect the seat belt control ECU connectors. Measure the resistance and voltage according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition H6-7 (+B) - Body ground B - Body ground Battery voltage Power switch off 11 to 14 V H6-8 (PGND) - Body ground W-B - Body ground Body ground Always Below 1 ohms H7-8 (IG1) - Body ground L - Body ground Seat belt control ECU power supply Power switch on (IG) 11 to 14 V Power switch off Below 1 V If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the connectors. Measure the voltage according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition H6-2 (MOR+) - H6-1 (MOR-) B - W Seat belt motor RH power supply Power switch on (IG) 4.0 to 8.5 V Power switch off Below 1 V H6-3 (MOL+) - H6-4 (MOL-) B - W Seat belt motor LH power supply Power switch on (IG) 4.0 to 8.5 V Power switch off Below 1 V If the result is not as specified, the ECU may be malfunctioning.
2. CHECK DRIVING SUPPORT ECU Disconnect the driving support ECU connector. Measure the resistance according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition H5-25 (GND) - Body ground W-B - Body ground Body ground Always Below 1 ohms H5-5 (PBSW) - Body ground L - Body ground Pre-collision brake cancel switch Pre-collision brake off switch on Below 1 ohms Pre-collision brake off switch off 10 kohms or higher If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the connector. Measure the voltage according to the value(s) in the table below. Terminal No. (Symbols) Wiring Color Terminal Description Condition Specified Condition H5-17 (CA2L) - H5-25 (GND) B - W-B CAN communication signal Power switch on (IG) Pulse generation (See waveform 1 (Scheme 292) ) H5-7 (MODE) - Body ground R - Body ground MODE signal Power switch on (IG) MODE switch off 11 to 14 V Power switch on (IG) MODE switch on Below 1 V H5-16 (LRDD) - Body ground SB - Body ground Driving support ECU communication signal Power switch on (IG) Pulse generation (See waveform 2 (Scheme 293) ) H5-38 (LRRD) - Body ground R - Body ground Driving support ECU communication signal Power switch on (IG) Pulse generation (See waveform 3 (Scheme 294) ) H5-23 (CCS) - H5-25 (GND) LG - W-B Cruise control main switch signal Power switch on (IG) 10 to 14 V H5-23 (CCS) - H5-25 (GND) LG - W-B Cruise control main switch signal Power switch on (IG), CANCEL switch on 6.6 to 10.1 V H5-23 (CCS) - H5-25 (GND) LG - W-B Cruise control main switch signal Power switch on (IG), Main switch on Below 1 V H5-39 (CA2H) - H5-25 (GND) L - W-B CAN communication signal Power switch on (IG) Pulse generation (See waveform 4 (Scheme 295) ) Waveform 1 CAN communication signal Item Content Driving Support ECU Terminal Name Between CA2L and GND Tester Range 1 V/DIV., 10 μsec./DIV. Condition Power switch on (IG) HINT: The waveform varies depending on the CAN communication signal. Waveform 2 Item Content Driving Support ECU Terminal Name Between LRDD and GND Tester Range 2 V/DIV., 10 μsec./DIV. Condition Power switch on (IG) Waveform 3 Item Content Driving Support ECU Terminal Name Between LRRD and GND Tester Range 2 V/DIV., 10 μsec./DIV. Condition Power switch on (IG) Waveform 4 CAN communication signal Item Content Driving Support ECU Terminal Name Between CA2H and GND Tester Range 1 V/DIV., 10 μsec./DIV. Condition Power switch on (IG) HINT: The waveform varies depending on the CAN communication signal.

DIAGNOSIS SYSTEM

1. CHECK DLC3 Check the DLC3. Refer to «GENERAL INFORMATION»(ref-568589-S28103458762013072300000) .
2. FUNCTION OF WARNING INDICATOR AND MESSAGE If the pre-collision system is not functioning properly, the driver is warned by the master warning indicator and multi-information display warning message on the combination meter. Master Warning Indicator Warning Message Detail DTC PCS Warning Indicator ON CHECK PCS SYSTEM This message appears when the seat belt control ECU and driving support ECU detects a system malfunction o Blinking OFF PCS TEMPORARILY NOT AVAILABLE This message appears when the seat belt control ECU is in fail-safe mode. Refer to «FAIL-SAFE CHART»(ref-568837-S30216697462013072300000) - ON Initial check The initial check occurs when the power switch is off for more than 2 seconds, and then turned on (IG). The initial check consists of a pre-collision system diagnostic check with a duration of approximately 3 seconds. If a malfunction is detected during the initial check, "CHECK PCS SYSTEM " or "PCS TEMPORARILY NOT AVAILABLE" is displayed on the multi-information display in the combination meter assembly. Constant check The seat belt control ECU and driving support ECU constantly monitor the pre-collision system for malfunctions after the power switch is turned on (IG) and initial check (approximately 3 seconds) is completed. "CHECK PCS SYSTEM" or "PCS TEMPORARILY NOT AVAILABLE" is displayed on the multi-information display in the combination meter assembly when the constant check detects malfunctions in the pre-collision system.

DTC CHECK / CLEAR

1. CHECK DTC Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Pre-Collision / Trouble Codes. Enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes. Check the details of the DTC(s). Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-568837-S00457208902013072300000) . HINT: As the driving support ECU and seat belt control ECU output DTCs for the pre-collision system, be sure to check the Pre-Collision and Pre-Collision 2 DTCs.
2. CLEAR DTC Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Pre-Collision / Trouble Codes. Enter the following menus: Body Electrical / Pre-Collision 2 / Trouble Codes. Clear the DTCs. HINT: As the driving support ECU and seat belt control ECU output DTCs for the pre-collision system, be sure to clear the Pre-Collision and Pre-Collision 2 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 power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Pre-Collision / Data List. Enter the following menus: Body Electrical / Pre-Collision 2 / Data List. Read the Data List according to the display on the Techstream. HINT: As the driving support ECU and seat belt control ECU both have Data List for the pre-collision system, be sure to check the Pre-Collision and Pre-Collision 2 Data Lists. PRE-COLLISION Tester Display Measurement Item/Range Normal Condition Diagnostic Note Driver Buckle SW Buckle switch status of driver side seat/ UNSET, SET or NG UNSET: Driver seat belt unfastened SET: Driver seat belt fastened NG: Indeterminate data - Passenger Buckle SW Buckle switch status of passenger side seat/ UNSET, SET or NG UNSET: Front passenger seat belt unfastened SET: Front passenger seat belt fastened NG: Indeterminate data - Driver Belt Control Seat belt control status of driver side seat/ STOP, ON or ERROR STOP: Control stopped ON: Controlled ERROR: Indeterminate data Seat belt (driver side) is fastened Passenger Belt Control Seat belt control status of passenger side seat/ STOP, ON or ERROR STOP: Control stopped ON: Controlled ERROR: Indeterminate data Seat belt (passenger side) is fastened Number of Trouble Code Number of past trouble codes/min: 0, max: 255 Number of DTCs will be displayed - PRE-COLLISION 2 Tester Display Measurement Item/Range Normal Condition Diagnostic Note Wiper Information Wiper operational status/ Unoperat, Oil off, Mist, Washer, Unknown, Intermittent, Lo, Hi The respective operational status displayed - Pre-Collision Brake OFF Switch Pre-collision brake off switch status/ ON or OFF ON: Pre-collision brake off switch on OFF: Pre-collision brake off switch off - Pre-Collision System Pre-collision system control/ Valid or Inval Valid: Pre-collision system control possible Inval: Pre-collision system control not possible - PCS Indicator "CHECK PCS SYSTEM" display request signal/ ON or OFF ON: "CHECK PCS SYSTEM" display requested OFF: "CHECK PCS SYSTEM" display not requested - PCS Disabled Indicator "PCS TEMPORARILY NOT AVAILABLE" display request signal/ ON or OFF ON: "PCS TEMPORARILY NOT AVAILABLE" display requested OFF: "PCS TEMPORARILY NOT AVAILABLE" display not requested - Pre-Collision Safety Warning Ind PCS system warning status/ ON or OFF ON: Pre-collision warning indicator on OFF: Pre-collision warning indicator off - Pre-Collision Safety Brake Ind PCS system "BRAKE!" alert status/ ON or OFF ON: PCS system "BRAKE!" alert on OFF: PCS system "BRAKE!" alert off - Pre-Collision Safety Warning Buz PCS system warning buzzer/ Valid or Inval Valid: PCS system warning buzzer operation possible Inval: PCS system warning buzzer operation not possible - Pre-Collision Brake Pre-collision brake function/ Valid or Inval Valid: Pre-collision brake operation possible Inval: Pre-collision brake operation not possible - Front Radar PSB Front radar-linked pre-collision seat belt activation signal/ ON or OFF ON: Front radar-linked pre-collision seat belt activated OFF: Front radar-linked pre-collision seat belt not activated Status changes when the pre-collision seat belt is activated before a collision PBA Start Pre-collision brake assist activation signal/ ON or OFF ON: Pre-collision brake assist activated OFF: Pre-collision brake assist not activated Signal status changes when the pre-collision brake assist is activated before a collision (Pre-collision brake will activate only in situations where the driver depresses the brake pedal) Brake Assist Standby Supplemental brake pressure signal/ ON or OFF ON: Supplemental brake pressure being provided OFF: Supplemental brake pressure not being provided Signal status changes when supplemental brake pressure is being provided after a collision is judged as unavoidable and before the brake pedal is depressed Pre-Collision Brake Control Pre-collision brake operational status/ ON or OFF ON: Pre-collision brake operating OFF: Pre-collision brake function not operating Status changes when pre-collision brake operates before a collision AVS Start AVS control activation status/ ON or OFF ON: AVS control activated OFF: AVS control not activated Status changes when the suspension is controlled (stiffened) prior to a collision CCS Cancel Automatic cancellation of cruise control during pre-collision brake activation/ ON or OFF ON: Cruise control automatically canceled OFF: Cruise control not automatically canceled - Front Radar-Dirt History Millimeter wave radar sensor assembly dirt history/ ON or OFF ON: History of excessive dirt OFF: No history of excessive dirt - Front Radar-Environment Hist Millimeter wave radar sensor temperature condition history/ Good or Bad Good: No history of excessive temperature Bad: History of excessive temperature - Curr Com PCS-WIL-R Driver seat active headrest ECU connection status/ without or with with: Driver seat active headrest ECU connected without: Driver seat active headrest ECU not connected Not Supported Curr Com PCS-WIL-L Front passenger seat active headrest ECU connection status/ without or with with: Front passenger seat active headrest ECU connected without: Front passenger seat active headrest ECU not connected Not Supported Curr Com Night View ECU Night view ECU connection status/ without or with with: Night view ECU connected without: Night view ECU not connected Not Supported Country# (DSS) Destination country for driving support computer/ JPN, NA, EURO, AUS, SAFC, OTHER, TWN, CHINA, THAI, GCC, NOFIX Actual country code - The Number of DTCs Number of DTCs/ 0 to 255 When system is normal: 0 When a malfunction is detected: More than 0
2. ACTIVE TEST HINT: Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Body Electrical / Pre-Collision / Active Test. Perform Active Test according to the display on the Techstream. HINT: The power switch must be turned on (IG) to proceed with the Active Test using the Techstream. PRE-COLLISION Tester Display Test Part Control Range Diagnostic Note Driver Seat Belt Motor Driver seat belt motor ON: Seat belt motor operates OFF: Seat belt motor does not operate Seat belt (driver side) is fastened Passenger Seat Belt Motor Passenger seat belt motor ON: Seat belt motor operates OFF: Seat belt motor does not operate Seat belt (front passenger side) is fastened Driver and Passenger Seat Belt Motor Driver and passenger seat belt motors ON: Seat belt motors operate OFF: Seat belt motors do not operate Seat belts (driver and front passenger sides) are fastened NOTE: The seat belt motor will only operate when the tongue plate is inserted into the buckle (seat belt fastened). To prevent overheating the belt motor, this test cannot be activated continuously. Operate the belt motor at an interval of 30 seconds or more.

DIAGNOSTIC TROUBLE CODE CHART

If a trouble code is displayed during the DTC check, inspect the trouble areas listed for that code in the table below and proceed to the appropriate article.

PRE-COLLISION SYSTEM

See also:
• REMOVAL
• REMOVAL