Lighting System (Diagnostics - Introduction): Diagnosis Lexus CT I

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

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

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. CUSTOMER PROBLEM ANALYSIS CHECK AND SYMPTOM CHECK NEXT: Go to next step
3. 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. NEXT: Go to next step
4. INSPECT CAN COMMUNICATION SYSTEM* Use the Techstream to check if the CAN communication system is functioning normally. Result Result Proceed to CAN communication system DTC is not output. A CAN communication system DTC is output. B B --> GO TO «CAN COMMUNICATION SYSTEM»(ref-568746-S15103859142013072300000) A: Go to next step
5. CHECK FOR DTC* Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-568605-S41597265672013072300000) . Result Result Proceed to DTC is not output. A DTC is output. B B --> Go to step 8 A: Go to next step
6. PROBLEM SYMPTOMS TABLE Refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE»(ref-568605-S19186653942013072300000) . 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 8 A: Go to next step
7. OVERALL ANALYSIS AND TROUBLESHOOTING* Data List / Active Test. Refer to «DATA LIST / ACTIVE TEST»(ref-568605-S30111884722013072300000) Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-568605-S33022028852013072300000) NEXT: Go to next step
8. ADJUST, REPAIR OR REPLACE NEXT: Go to next step
9. CONFIRMATION TEST NEXT --> END

PROBLEM SYMPTOMS TABLE

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.

HEADLIGHT AND TAILLIGHT (EXCEPT LED HEADLIGHT)

HEADLIGHT AND TAILLIGHT (FOR LED HEADLIGHT)

STOP LIGHT

1. *1: The stop lights may always come on due to abnormality of the brake booster with master cylinder.

FRONT FOG LIGHT

BACK-UP LIGHT

TURN SIGNAL LIGHT

1. *1: w/ Seat Memory Switch

HAZARD WARNING LIGHT

AUTOMATIC LIGHT CONTROL SYSTEM

LIGHT AUTO TURN-OFF SYSTEM

DAYTIME RUNNING LIGHT SYSTEM (W/ DAYTIME RUNNING LIGHT)

DOOR MIRROR FOOT LIGHT (W/ SEAT MEMORY POSITION)

DOOR MIRROR FOOT LIGHT (W/O SEAT MEMORY POSITION)

AUTOMATIC HEADLIGHT BEAM LEVEL CONTROL

Note. Initialize the headlight leveling ECU assembly after the vehicle height changes due to replacement of the suspension or after performing such operations as removal and reinstallation or replacement of the rear height control sensor sub-assembly. When the headlight leveling ECU assembly is replaced, initialization is also necessary.

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

1. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Disconnect the instrument panel junction block assembly and main body ECU (multiplex network body ECU) connectors. Measure the voltage according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition 2B-25 - Body ground B - Body ground IG power supply Power switch on (IG) 11 to 14 V Power switch off Below 1 V 2C-18 (BECU) - Body ground B - Body ground Auxiliary battery power supply Power switch off 11 to 14 V 2E-1 - Body ground W - Body ground Auxiliary battery power supply Power switch off 11 to 14 V If the result is not as specified, there may be a malfunction in the wire harness. Measure the resistance according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition 2B-6 (GND1) - Body ground W-B - Body ground Ground Always Below 1 ohms H17-3 (GND2) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction in the wire harness. Reconnect the instrument panel junction block assembly and main body ECU (multiplex network body ECU) connectors. Measure the voltage and check for pulses according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition 2C-20 (PKB) - Body ground R - Body ground Parking brake switch input Parking brake switch on Below 1 V Parking brake switch off 11 to 14 V 2C-32 (HRLY) - Body ground G - Body ground Headlight relay drive output Light control switch in head position Below 1 V Light control switch not in head position 11 to 14 V H16-15 (DRL)*1 - Body ground Y - Body ground Daytime running light system drive output Daytime running light system operates Below 1 V Daytime running light system not operates 11 to 14 V H17-2 (LSWR) - Body ground GR - Body ground Rear door unlock detection switch RH input Rear door RH locked Pulse generation Rear door RH unlocked Below 1 V 2C-22 (DIM) - Body ground Y - Body ground High beam headlights drive output Dimmer switch in high or high flash position Below 1 V Dimmer switch in low position 11 to 14 V H16-8 (HF) - Body ground LG - Body ground Dimmer switch high flash position signal input Dimmer switch in high flash position Below 1 V Dimmer switch not in high flash position Pulse generation H16-20 (CLTB) - Body ground R - Body ground Automatic light control sensor power supply output Power switch off Below 1 V Power switch on (IG) and light control switch in AUTO position 11 to 14 V H16-21 (CLTS) - Body ground W - Body ground Automatic light control sensor signal input Power switch off Below 1 V Automatic light control system operates Pulse generation (See waveform 1 (Scheme 2) ) H16-27 (FFOG) - Body ground LG - Body ground Front fog light switch input Front fog light switch on Below 1 V Front fog light switch off Pulse generation H16-28 (A) - Body ground W - Body ground Light control switch AUTO position signal input Light control switch in AUTO position Below 1 V Light control switch not in AUTO position Pulse generation H16-29 (HEAD) - Body ground L - Body ground Light control switch head position input Light control switch in head position Below 1 V Light control switch not in head position and power switch off Pulse generation Light control switch not in head position and power switch on (IG) 11 to 14 V H16-30 (TAIL) - Body ground Y - Body ground Light control switch tail position signal input Light control switch in tail or head position Below 1 V Light control switch in neither tail nor head position, and power switch off Pulse generation Light control switch in neither tail nor head position, and power switch on (IG) 11 to 14 V HINT: *1: w/ Daytime Running Light System If the result is not as specified, the main body ECU (multiplex network body ECU) or instrument panel junction block assembly may have a malfunction. Waveform 1 Item Content Tool setting 5 V/DIV., 5 ms./DIV. HINT: If the ambient light becomes brighter, width A becomes narrower.
2. CHECK POWER MANAGEMENT CONTROL ECU Measure the resistance and voltage according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition A19-15 (BL) - H3-6 (E1) LG - W-B Back up light Power switch on (IG), reverse (R) selected 11 to 14 V If the result is not as specified, the headlight leveling ECU assembly may have a malfunction.
3. CHECK HEADLIGHT LEVELING ECU ASSEMBLY Disconnect the A46 headlight leveling ECU assembly connector. Measure the voltage and resistance according to the value(s) in the table below. STANDARD VOLTAGE Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition A46-1 (IG) - Body ground LG - Body ground IG power supply Power switch off Below 1 V Power switch on (IG) 11 to 14 V STANDARD RESISTANCE Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition A46-9 (E1) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the A48 headlight leveling ECU assembly connector. Measure the resistance and voltage according to the value(s) in the table below. STANDARD RESISTANCE Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition A46-21 (SGR) - Body ground Y - Body ground Rear height control sensor ground Always Below 1 ohms A46-23 (RH-) - Body ground BR - Body ground Leveling motor RH ground Always Below 1 ohms A46-24 (LH-) - Body ground LG - Body ground Leveling motor LH ground Always Below 1 ohms STANDARD VOLTAGE Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition A46-3 (HDLP) - Body ground V - Body ground Low beam headlight signal input Low beam headlights on Below 1.5 V Low beam headlights off Above 5 V A46-5 (INIT) - Body ground B - Body ground Initialization signal input Terminals LVL and GND of DLC3 connected Below 1 V Terminals LVL and GND of DLC3 not connected Approx. 5 V A46-6 (WNG) - Body ground L - Body ground Warning indicator drive output Warning indicator on Below 1 V Warning indicator off 11 to 14 V A46-10 (RH+) - Body ground W - Body ground Leveling motor RH power supply Power switch off Below 1 V Power switch on (IG) 11 to 14 V A46-11 (LH+) - Body ground R - Body ground Leveling motor LH power supply Power switch off Below 1 V Power switch on (IG) 11 to 14 V A46-12 (SBR) - Body ground P - Body ground Rear height control sensor power supply Power switch off Below 1 V Power switch on (IG) 4.75 to 5.25 V A46-16 (SPDR) - Body ground V - Body ground Vehicle speed signal input Vehicle is driven at approx. 20 km/h (12mph) Pulse generation (See waveform 1 (Scheme 5) ) A46-17 (RHT) - Body ground B - Body ground Leveling motor RH operation signal input With low beam headlights on, vehicle height not changed Below 1 V With low beam headlights on, change vehicle height and keep for more than 3 seconds 1.0 to 14.4 V A46-18 (LHT) - Body ground G - Body ground Leveling motor LH operation signal input With low beam headlights on, vehicle height not changed Below 1 V With low beam headlights on, change vehicle height and keep for more than 3 seconds 1.0 to 14.4 V A46-19 (SHRL) - Body ground SB - Body ground Rear height control sensor signal input Power switch off Below 1 V Power switch on (IG) 0.5 to 4.5 V If the result is not as specified, the headlight leveling ECU assembly may have a malfunction. Waveform 1 Item Content Tool setting 2 V/DIV., 2 ms./DIV. Vehicle condition Driving at approx. 20 km/h (12 mph)
4. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY (DRIVER SIDE) Disconnect the K7 connector. Measure the voltage according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connector disconnected. STANDARD VOLTAGE Tester Connection Wiring Color Terminal Description Condition Specified Condition K7-14 (BDR) - Body ground L - Body ground +B power supply Power Switch off 11 to 14 V K7-6 (CPUB) - Body ground LG - Body ground +B power supply Power Switch off 11 to 14 V K7-5 (SIG) - Body ground Y - Body ground Ignition power supply Power switch off --> on (IG) Below 1 V --> 11 to 14 V If the result is not as specified, there may be a malfunction on the wire harness side. Measure the resistance according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connector disconnected. STANDARD RESISTANCE Tester Connection Wiring Color Terminal Description Condition Specified Condition K7-7 (GND) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the K7 connector. Measure the voltage according to the value(s) in the table below. STANDARD VOLTAGE Tester Connection Wiring Color Terminal Description Condition Specified Condition z6-2 (MLP) - z6-12 (-) Y - BR Door mirror foot light drive output Door mirror foot light off --> on Below 1 V --> 11 to 14 V
5. CHECK OUTER MIRROR CONTROL ECU ASSEMBLY (PASSENGER SIDE) Disconnect the J8 connector. Measure the voltage according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connector disconnected. STANDARD VOLTAGE Tester Connection Wiring Color Terminal Description Condition Specified Condition J8-6 (CPUB) - Body ground LG - Body ground +B power supply Power switch off 11 to 14 V J8-14 (BDR) - Body ground L - Body ground +B power supply Power switch off 11 to 14 V J8-5 (SIG) - Body ground Y - Body ground Ignition power supply Power switch off --> on (IG) Below 1 V --> 11 to 14 V If the result is not as specified, there may be a malfunction on the wire harness side. Measure the resistance according to the value(s) in the table below. HINT: Measure the values on the wire harness side with the connector disconnected. STANDARD RESISTANCE Tester Connection Wiring Color Terminal Description Condition Specified Condition J8-7 (GND) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side. Reconnect the J8 connector. Measure the voltage according to the value(s) in the table below. STANDARD VOLTAGE Tester Connection Wiring Color Terminal Description Condition Specified Condition z7-2 (MLP) - z7-12 (-) Y - BR Door mirror foot light drive output Door mirror foot light off --> on Below 1 V --> 11 to 14 V

DIAGNOSIS SYSTEM

1. DESCRIPTION Lighting system data and the Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and to repair.
2. CHECK DLC3 Check the DLC3. Refer to «GENERAL INFORMATION»(ref-568589-S28103458762013072300000) .
3. 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.

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 / Trouble Codes. Check for 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 / Trouble Code. Clear the 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, actuator 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 / (desired system) / Data List. Read the Data List according to the display on the Techstream. MAIN BODY Tester Display Measurement Item/Range Normal Condition Diagnostic Note Parking Brake SW Parking brake switch signal/ON or OFF ON: Parking brake switch on OFF: Parking brake switch off - Hazard Switch Hazard switch signal/ON or OFF ON: Hazard switch on OFF: Hazard switch off - Dimmer SW Dimmer switch high position signal/ON or OFF ON: Dimmer switch in high or high flash position OFF: Dimmer switch in low position - Passing Light SW Dimmer switch high flash position (pass) signal/ON or OFF ON: Dimmer switch in high flash position OFF: Dimmer switch not in high flash position - Front Fog Light SW Front fog light switch signal/ON or OFF ON: Front fog light switch on OFF: Front fog light switch off - Auto Light SW Light control switch AUTO position signal/ON or OFF ON: Light control switch in AUTO position OFF: Light control switch not in AUTO position - Head Light SW (Head) Light control switch head position signal/ON or OFF ON: Light control switch in head position OFF: Light control switch not in head position - Head Light SW (Tail) Light control switch tail position signal/ON or OFF ON: Light control switch in tail or head position OFF: Light control switch in neither tail nor head position - Illumination Rate Info Illumination rate information/0 ms. to 2162.65 ms. Value is output according to ambient light levels - Mirr-Foot-Lgt Approached Lights up the door mirror foot lights when a key enters any actuation area around the doors./ON or OFF Customize setting displayed - Mirr-Foot-Lgt Unlocked Lights up the door mirror foot lights when doors are unlocked using a mechanical key or door control transmitter./ON or OFF Customize setting displayed - Mirr-Foot-Lgt w/Master SW Lights up the door mirror foot lights when the driver side door control switch on the multiplex network master switch assembly is pushed to the unlock position. Lights up the door mirror foot lights when the driver side door control switch on the multiplex network master switch assembly is pushed to the unlock position./ON or OFF Customize setting displayed - Mirror Foot Light Time Lighting time of the door mirror foot lights/7.5 s, 15 s, 30 s or 0 s Customize setting displayed - Exterior Light Control Changes the door mirror foot light control/ON or OFF Customize setting displayed - Response Time*1 Delay timing of lighting the taillights when the automatic light control sensor detects brightness change/0.1 s or 1.0 s Customize setting displayed - Sensitivity Sensitivity of the automatic light control system/Light2, Light1, Normal, Dark1 or Dark2 Customize setting displayed - DRL Function*2 DRL function/ON or OFF Customize setting displayed - Disp Ex ON Sen Ambient brightness level required to dim display lights (combination meter, navigation display etc.)/Light2, Light1, Normal, Dark1 or Dark2 Customize setting displayed - Disp Ex OFF Sen Ambient brightness level required to cancel dimming display lights (combination meter, navigation display etc.)/Light2, Light1, Normal, Dark1 or Dark2 Customize setting displayed - Light Auto OFF Delay Light auto OFF delay/Off, 30 s, 60 s or 90 s Customize setting displayed - HL AUTO LEVELING Tester Display Measurement Item/Range Normal Condition Diagnostic Note Headlight Low Beam State Low beam headlight state/ON or OFF ON: Low beam headlights on OFF: Low beam headlights off - +B IG power supply voltage value/0 to 19.75 V 11 to 14 V - Height Sens Pw Supply Val Height control sensor power supply value/0 to 6.25 V Approx. 5 V - Rr Height Sens Signal Val Rear height control sensor signal value/0 to 5 V Approx. 2.5 V (When vehicle is level) Value changes according to vehicle height Vehicle Speed Vehicle speed/0 to 327.67 km/h (203.61 mph) Condition can be displayed - Rear Height Adjust Valid Flag Rear height adjustment range/VALID or INVALID Condition can be displayed - Init Writing Count Number of times for initialization/0 to 255 Condition can be displayed - Sensor Initialization Hist Sensor Initialization History/not comp, 10%, 25%, 50%, 75%, 100% or complied Condition can be displayed - Number Of Trouble Codes Number of trouble codes/0 to 255 Condition can be displayed - *1: w/o DRL *2: The headlight dimmer switch has DRL OFF function
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 / (desired system) / Active Test. Perform the Active Test according to the display on the Techstream. MAIN BODY Tester Display Test Part Control Range Diagnostic Note Hazard Hazard warning lights ON/OFF - Daytime Running Light Daytime running lights ON/OFF - Side Mirror Foot Light*1 Door mirror foot lights ON/OFF - Taillight Relay Taillight relay ON/OFF - Headlight Relay Headlight relays ON/OFF - Head Light Hi High beam headlights ON/OFF - Front Fog Light Relay Front fog light relay ON/OFF Light control switch is in head position *1: w/o Seat Position Memory HL AUTO LEVELING Tester Display Test Part Control Range Diagnostic Note Drive The Leveling Motor UP*2 Leveling motor upward operation ON/OFF ON: Move up OFF: Stop Drive The Leveling Motor DOWN*2 Leveling motor downward operation ON/OFF ON: Move down OFF: Stop *2: Perform the active test with the power switch on (READY). MIRROR L*3 Tester Display Test Part Control Range Diagnostic Note Foot Light Door mirror foot light LH ON/OFF - MIRROR R*3 Tester Display Test Part Control Range Diagnostic Note Foot Light Door mirror foot light RH ON/OFF - *3: w/ Seat Position Memory

DIAGNOSTIC TROUBLE CODE CHART

LIGHTING SYSTEM