Cruise Control: Overview Lexus RX II рестайлинг

SYSTEM DESCRIPTION

1. CRUISE CONTROL SYSTEM This system is controlled by the hybrid vehicle control ECU, and is activated by the throttle position sensor and motor. The hybrid vehicle control ECU controls the following functions: ON-OFF, -/SET, +/RES, CANCEL, vehicle speed operation, motor output control, and overdrive control. The hybrid vehicle control ECU compares the driving vehicle speed from the speed sensor with the stored vehicle speed set through the cruise control main switch assy. The hybrid vehicle control ECU controls the throttle valve motor of the throttle position sensor and motor to close the valve when the driving speed is less than the stored speed. The hybrid vehicle control ECU receives signals such as ON-OFF, -/SET, +/RES, and CANCEL from the cruise control main switch assy and executes them. The hybrid vehicle control ECU illuminates the combination meter's CRUISE main indicator light when it receives the cruise control main switch ON signal. The hybrid vehicle control ECU cancels the cruise control system when the brake pedal is depressed and the hybrid vehicle control ECU receives the stop light switch signal. The hybrid vehicle control ECU cancels the cruise control system when the shift lever is moved from D (5th, 4th 3rd, 2nd or 1st gear) to N, and the hybrid vehicle control ECU receives the PNP switch signal.
2. LIMIT CONTROL Low speed limit The lowest possible limit of the speed setting range is set at approximately 40 km/h (25 mph). The cruise control system cannot be set when the driving vehicle speed is below the low speed limit. Cruise control operation will be automatically canceled. High speed limit The highest possible limit of the speed setting range is set at approximately 200 km/h (125 mph). The cruise control system cannot be set when the driving vehicle speed is over the high speed limit. Also, +/RES cannot be used to increase speed beyond the high speed limit.
3. OPERATION OF CRUISE CONTROL The cruise control main switch operates 7 functions: SET, COAST, TAP-DOWN, RESUME, ACCEL, TAP-UP, and CANCEL. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP and ACCEL functions are operated with the same switch. The cruise control main switch assy is an automatic return type switch which turns on only while operating it in each arrow direction and turns off after releasing it. SET CONTROL Vehicle speed is stored and constant speed control is maintained when pushing the switch to -/SET while driving with the cruise control main switch ON (the CRUISE main indicator light is on), and the vehicle speed is within the set speed range (between the low and high speed limits). COAST CONTROL When the cruise control main switch is set to -/SET and held in that position while the cruise control system is operating, the hybrid vehicle control ECU sends a "throttle valve opening angle 0°" demand signal to the cruise control system. Then the vehicle speed, when the cruise control main switch is released, is stored and maintained. HINT: An actual throttle valve opening angle of 0° is not possible due to the idle speed control, etc. TAP-DOWN CONTROL When tapping down the cruise control main switch to -/SET (for approximately 0.5 second) while the cruise control system is in operation, the stored vehicle speed decreases each time by approximately 1.6 km/h (1.0 mph). When the cruise control main switch is released from -/SET and the difference between the driving and stored vehicle speed is more than 5 km/h (3 mph), the vehicle speed is stored and constant speed control is maintained. ACCELERATION CONTROL The throttle valve motor of the throttle position sensor and motor is instructed by the hybrid vehicle control ECU to open the throttle valve when +/RES on the cruise control main switch is pressed and held while the cruise control system is in operation. When the cruise control main switch is released from +/RES, the vehicle speed is stored and the vehicle is controlled at a constant speed. TAP-UP CONTROL When tapping up the cruise control main switch to +/ RES (for approximately 0.5 second) while the cruise control system is in operation, the stored vehicle speed increases each time by approximately 1.6 km/h (1.0 mph). However, when the difference between the driving and the stored vehicle speed is more than 5 km/h (approximately 3.1 mph), the stored vehicle speed will not be changed. RESUME CONTROL If cruise control operation was canceled with the stop light switch or the CANCEL switch, and if driving speed is within the limit range, pushing the cruise control main switch to +/RES restores vehicle speed memorized at the time of cancellation, and maintains constant speed control. MANUAL CANCEL CONTROL Performing any of the following cancels the cruise control system while in operation (the stored vehicle speed in the hybrid vehicle control ECU is maintained). Depressing the brake pedal Moving the shift lever to any position except D (6th, 5th and 4th gears) Pushing the cruise control main switch to CANCEL Turning the cruise control main switch OFF (the stored vehicle speed in the hybrid vehicle control ECU is not maintained).
4. AUTO CANCEL (FAIL-SAFE) This system has an automatic cancellation function (fail-safe) (See «FAIL-SAFE CHART» ).

DESCRIPTION

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a 4 pulse signal and outputs it to the hybrid vehicle control ECU via the combination meter. The hybrid vehicle control ECU determines the vehicle speed based on the frequency of these pulse signals.

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DTC TROUBLE DETECTION CHART

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1. CHECK SPEEDOMETER (OPERATION) Drive the vehicle and check if operation of the speedometer in the combination meter is normal. OK: Actual vehicle speed and the speed indicated on the speedometer are the same. HINT: The vehicle speed sensor is operating normally if the speedometer display is normal. NG: CHECK SPEEDOMETER CIRCUIT (See «Speedometer Malfunction» ) OK: Go to next step
2. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the ignition switch on. Select the item "VEHICLE SPD" in the DATA LIST and check that the speed displayed on the tester screen is the same as the one indicated on the combination meter. CCS: TESTER DISPLAY DIAGNOSTIC CHART Tester Display Measurement Item/Range Normal Condition Diagnostic Note VEHICLE SPD Cruise control vehicle speed/min.: 0 km/h (0 mph) max.: 255 km/h (158 mph) Actual vehicle speed - OK: The speed displayed on the tester screen is almost the same as the speed the one indicated on the combination meter. NG: GO TO step 3 OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»
3. INSPECT HYBRID VEHICLE CONTROL ECU (SPD VOLTAGE) Shift the lever to the neutral position. Jack up the vehicle. Turn the ignition switch on. Measure the voltage between the specified terminals of the H29 and H31 hybrid vehicle control ECU connectors as the wheel is turned slowly. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition H29-24 (SPDI) - H31-5 (E1) Generated intermittently Refer to HINT below. HINT: The output voltage should fluctuate up and down similarly to the diagram on the left when the wheel is turned slowly. NG: GO TO step 4 OK: REPLACE HYBRID VEHICLE CONTROL ECU (See «HYBRID VEHICLE CONTROL ECU»(/lexus/rx/ii-2006-2009/remont/engine-control-systems/#hybrid-vehicle-control-p310) )
4. CHECK HARNESS AND CONNECTOR Disconnect the H29 connector of the hybrid vehicle control ECU. Disconnect the C8 connector of the combination meter. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Value H29-24 (SPDI) - C8-6 Always Below 1 ohms H29-24 (SPDI) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE COMBINATION METER ECU (See «COMBINATION METER» )

When the brake pedal is depressed, the stop light switch sends a signal to the hybrid vehicle control ECU. When the hybrid vehicle control ECU receives this signal, it cancels the cruise control. Fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is applied, voltage is normally applied to terminal STP of the hybrid vehicle control ECU through the STOP SW fuse and the stop light switch, and the hybrid vehicle control ECU turns the cruise control off.

DTC TROUBLE DETECTION CHART

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the ignition switch on, and turn the intelligent tester main switch on. Check the DATA LIST for proper functioning of the stop light switch. CCS: TESTER DISPLAY DIAGNOSTIC CHART Tester Display Measurement Item/Range Normal Condition Diagnostic Note STP LIGHT SW M Stop light switch signal (Main CPU) / ON or OFF ON: Brake pedal depressed OFF: Brake pedal released - OK: When brake pedal operation is performed the results will be same as above. OK: REPLACE HYBRID VEHICLE CONTROL ECU NG: Go to next step
2. INSPECT STOP LIGHT SWITCH Disconnect the stop light switch connector. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Switch Condition Specified Condition 1 - 2 Switch pin not pushed Below 1 ohms 3 - 4 Switch pin not pushed 10 kohms or higher 1 - 2 Switch pin pushed 10 kohms or higher 3 - 4 Switch pin pushed Below 1 ohms NG: REPLACE STOP LIGHT SWITCH OK: Go to next step
3. CHECK WIRE HARNESS (STOP LIGHT SWITCH - BATTERY) Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition S13-2 - Body ground Always 10 to 14 V S13-3 - Body ground Engine switch on (IG) 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK HYBRID VEHICLE CONTROL ECU Reconnect the stop light switch connector. Disconnect the H29 connector from the hybrid vehicle control ECU. Turn the ignition switch on. Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Brake Pedal Condition Condition H29-31 (STP) - Body ground Depressed 10 to 14 V H29-31 (STP) - Body ground Released Below 1 V H29-25 (ST1-) - Body ground Depressed Below 1 V H29-25 (ST1-) - Body ground Released 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (STOP LIGHT SWITCH -HYBRID VEHICLE CONTROL ECU) OK: REPLACE HYBRID VEHICLE CONTROL ECU

This DTC indicator the internal abnormalities of the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

HINT

The hybrid vehicle control ECU receives signals from each sensor to control all functions of the cruise control system. When a trouble code is detected, the fail-safe function remains on until the engine switch is turned off.

The cruise control main switch operates 7 functions: SET, COAST, TAP-DOWN, RESUME, ACCEL, TAP-UP, and CANCEL. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP and ACCEL functions are operated with the same switch. The cruise control main switch is an automatic return type switch which turns on only while operating it in each arrow direction and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. Then the ECM reads the resistance value that has been changed by the switch operation to control SET, COAST, RESUME, ACCEL and CANCEL.

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the ignition switch on, and turn the intelligent tester main switch on. Check the DATA LIST for proper functioning of the cruise control main switch. CCS: TESTER CONNECTION SPECIFIED CONDITION Tester Display Measurement Item/Range Normal Condition Diagnostic Note MAIN SW (MAIN) Main switch signal (Main CPU) / ON or OFF ON: Main switch ON (Pushed on) OFF: Main switch OFF (Pushed off) - CANCEL SW CANCEL switch signal / ON or OFF ON: CANCEL switch ON OFF: CANCEL switch OFF - SET/COAST SW -/SET switch signal / ON or OFF ON: -/SET switch ON OFF: -/SET switch OFF - RES/ACC SW +/RES switch signal / ON or OFF ON: +/RES switch ON OFF: +/RES switch OFF - OK: When cruise control main switch operation is performed the results will be same as above. Result: RESULT REFERENCE Result Proceed to OK A NG (All items are defective.) B NG (One to four items are defective.) C A: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C: REPLACE CRUISE CONTROL MAIN SWITCH B: Go to next step
2. INSPECT CRUISE CONTROL MAIN SWITCH Disconnect the cruise control main switch connector. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Switch Condition Specified Condition 1 - 3 Neutral 10 kohms or higher 1 - 3 +/RES 235 to 245 ohms 1 - 3 -/SET 620 to 640 ohms 1 - 3 CANCEL 1,510 to 1,570 ohms 1 - 3 Main Switch ON Below 1 ohms NG: REPLACE CRUISE CONTROL MAIN SWITCH OK: Go to next step
3. INSPECT SPIRAL CABLE NOTE: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the page shown in the brackets. HINT: Removal (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Installation (See «INSTALLATION»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Remove the spiral cable. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Spiral Cable Position Specified Condition A-3 - C13-1 (CCS) Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right A-4 - C13-2 (ECC) Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right HINT: The spiral cable makes a maximum of approximately 5 rotations. NG: REPLACE SPIRAL CABLE OK: Go to next step
4. CHECK WIRE HARNESS (SPIRAL CABLE - HYBRID VEHICLE CONTROL ECU AND BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition C13-1 (CCS) - H29-26 (CCS) Always Below 1 ohms H29-26 (CCS) - Body ground Always 10 kohms or higher C13-1 (CCS) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

1. The hybrid vehicle control ECU detects a cruise control switch signal and sends it to the combination meter via CAN and BEAN. Then the CRUISE main indicator light comes on.
2. The CRUISE main indicator light circuit uses CAN and BEAN for communication. If there is a malfunction in this circuit, check for DTCs in the CAN communication system and multiplex communication system before troubleshooting this circuit.

Connecting terminals TC and CG of the DLC3 causes the system to enter self-diagnostic mode. If a malfunction is present, DTCs will be output.

HINT

When a particular warning light remains blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in the relevant ECU is suspected.

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1. CHECK WIRE HARNESS (TC of DLC3 - HYBRID VEHICLE CONTROL ECU) Disconnect the D1 connector from the DLC3 and H29 connector from the hybrid vehicle control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition H29-3 (TC) - D1-13 (TC) Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - HYBRID VEHICLE CONTROL ECU) OK: Go to next step
2. CHECK WIRE HARNESS (CG of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester connection Condition Specified condition D1-4 (CG) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - BODY GROUND) OK: Go to next step
3. CHECK WIRE HARNESS (TC of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Condition Condition Specified Condition D1-13 (TC) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE WIRE HARNESS OR EACH ECU OK: REPLACE HYBRID VEHICLE CONTROL ECU

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. The skid control ECU converts these wheel speed signals into a 4 pulse signal and outputs it to the hybrid vehicle control ECU via the combination meter. The hybrid vehicle control ECU determines the vehicle speed based on the frequency of these pulse signals.

DTC TROUBLE DETECTION CHART

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1. CHECK SPEEDOMETER (OPERATION) Drive the vehicle and check if operation of the speedometer in the combination meter is normal. OK: Actual vehicle speed and the speed indicated on the speedometer are the same. HINT: The vehicle speed sensor is operating normally if the speedometer display is normal. NG: CHECK SPEEDOMETER CIRCUIT (See «Speedometer Malfunction» ) OK: Go to next step
2. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the ignition switch to the ON position. Select the item "VEHICLE SPD" in the DATA LIST and check that the speed displayed on the tester screen is the same as the one indicated on the combination meter. LASER CRUISE: TESTER DISPLAY DIAGNOSTIC CHART Item Measurement Item/Display (Range) Normal Condition Diagnostic Note VEHICLE SPD Cruise control vehicle speed/min.: 0 km/h (0 mph) max.: 255 km/h (158 mph) Actual vehicle speed - OK: The speed displayed on the tester screen is almost the same as the speed the one indicated on the combination meter. NG: GO TO step 3 OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN «PROBLEM SYMPTOMS TABLE»
3. INSPECT HYBRID VEHICLE CONTROL ECU (SPD VOLTAGE) Shift the lever to the neutral position. Jack up the vehicle. Turn the ignition switch to the ON position. Measure the voltage between the specified terminals of the H29 and H31 hybrid vehicle control ECU connectors as the wheel is turned slowly. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition H29-24 (SPDI) - H31-5 (E1) Generated intermittently Refer to HINT below. HINT: The output voltage should fluctuate up and down similarly to the diagram on the left when the wheel is turned slowly. NG: GO TO step 4 OK: REPLACE HYBRID VEHICLE CONTROL ECU (See «HYBRID VEHICLE CONTROL ECU»(/lexus/rx/ii-2006-2009/remont/engine-control-systems/#hybrid-vehicle-control-p310) )
4. CHECK HARNESS AND CONNECTOR Disconnect the H29 connector of the hybrid vehicle control ECU. Disconnect the C8 connector of the combination meter. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Value H29-24 (SPDI) - C8-6 Always Below 1 ohms H29-24 (SPDI) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE COMBINATION METER ECU (See «COMBINATION METER» )

When the brake pedal is depressed, the stop light switch sends a signal to the hybrid vehicle control ECU. When the hybrid vehicle control ECU receives this signal, it cancels the cruise control. The fail-safe function operates to enable normal driving even if there is a malfunction in the stop light signal circuit. The cancellation condition occurs when voltage is applied to terminal STP. When the brake is applied, voltage is normally applied to terminal STP of the hybrid vehicle control ECU through the STOP SW fuse and the stop light switch, and the hybrid vehicle control ECU turns the cruise control off.

DTC TROUBLE DETECTION CHART

The hybrid vehicle control ECU receives the brake demand signal from the distance control ECU (cruise control ECU) and transmits it to the skid control ECU.

The skid control ECU receives a signal from the hybrid vehicle control ECU and operates the brake actuator.

The skid control ECU operates the brake actuator and illuminates the stop light by operating the BRK relay at the same time.

DTC TROUBLE DETECTION CHART

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1. CHECK BRK RELAY Remove the BRK relay from the engine room R/B No. 1. Check operation of the BRK relay. Standard resistance TERMINALS NO. AND SPECIFIED CONDITION Terminal No. Condition Specified value 3 - 5 Always 10 kohms or higher 3 - 5 When battery voltage is applied to terminal 1 and 2. Below 1 ohms NG: REPLACE BRK RELAY OK: Go to next step
2. CHECK WIRE HARNESS AND CONNECTOR (BRK RELAY - BATTERY) Disconnect the connector from the engine room R/B. Measure the voltage according to the value(s) in the table below. Standard voltage TERMINALS NO. AND SPECIFIED CONDITION Terminal No. Condition Specification 5 - Body ground Always 10 to 14 V 2 - Body ground Ignition switch on 10 to 14 V 2 - Body ground Ignition switch off Below 1 V NG: CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED FAILURE RELAY (BRK RELAY) OK: Go to next step
3. CHECK WIRE HARNESS AND CONNECTOR (BRK RELAY - SKID CONTROL ECU) Disconnect the connectors from the skid control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TERMINALS NO. AND SPECIFIED CONDITION Terminal No. Condition Specification 4 - S39-14 (STP) Always Below 1 ohms 4 - Body ground Always 10 kohms or higher 3 - S40-24 (EXI) Always Below 1 ohms 3 - Body ground Always 10 kohms or higher 1 - S41-11 (CR) Always Below 1 ohms 1 - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE SKID CONTROL ECU

This DTC indicates a malfunction in the hybrid vehicle control ECU.

HINT

The hybrid vehicle control ECU receives signals from each sensor to control all the functions of the cruise control with the microcomputer. When a malfunction is detected, fail-safe remains on until the engine switch is turned off.

DTC TROUBLE DETECTION CHART

The laser sensor emits laser beams towards an object in front and measures the distance and direction of the object by receiving the beam reflections. Based on the reflections, the sensor calculates the difference in speed between your own vehicle and an object in front. This data is transmitted to the distance control ECU (cruise control ECU).

DTC TROUBLE DETECTION CHART

HINT

The laser sensor monitors the laser emission and reception by itself. This DTC is detected when it cannot monitor.

When rain drops or snowflakes strike the laser sensor face, the distance between the vehicle in front and your own vehicle cannot be measured correctly.

The dynamic laser cruise control system functions by detecting the reflector of the vehicle directly in front. In the following cases, the system may not be able to detect the vehicle in front and may not properly maintain the correct vehicle-to-vehicle distance.

1. The vehicle in front is a tall trailer.
2. The back of the vehicle in front is extremely dirty.
3. Emission from the vehicle in front or from other lanes are heavy.
4. The vehicle in front has no reflector.
5. The laser sensor is receiving a strong flash of light (sunlight, etc.).

This DTC is output when the scanning angle of the laser sensor is incorrect.

This DTC is also output when the laser sensor optical axis is in an incorrect position is detected.

DTC TROUBLE DETECTION CHART

HINT

If the optical axis deviates to the upper/lower side +/- 2° or more and/or the right/left side +/- 4° or more, this DTC is detected.

The Skid control ECU receives the alarm demand signal from the ECU and operates the skid control buzzer. The buzzer sounds to warn that the distance between the vehicle in front and your own vehicle is shortening.

DTC TROUBLE DETECTION CHART

HINT

If the vehicle ahead in the same lane significantly decreases its speed or another vehicle moves in front of your own vehicle, adequate deceleration cannot be applied and the vehicle-to-vehicle distance will shorten. At this time, the system sounds the buzzer and the master warning light blinks to inform the driver. This circuit uses CAN communication. Therefore, if there are any malfunctions in the communication circuit, one or more DTCs in the CAN communication system are output.

This DTC is output when the VSC system has a problem. Check the VSC system when this DTC is output.

DTC TROUBLE DETECTION CHART

The distance control ECU receives information about the area in front of the vehicle from the laser sensor and then sends a brake control demands signal (deceleration demand) and diagnosis signals, such as laser sensor grime signals or laser sensor malfunction signals, to the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

The hybrid vehicle control ECU receives signals from each sensor and ECU, then sends signals such as the cruise control operation signal, brake control operation signal and laser light emission prohibiting signal, etc. to the distance control ECU. The hybrid vehicle control ECU is the only component that has a function to record and output the DTCs in the dynamic laser cruise control system. Therefore, if the distance control ECU detects a communication error from the hybrid vehicle control ECU, it sends the malfunction signal back to the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

In the dynamic laser cruise control system, the hybrid vehicle control ECU and the distance control ECU (cruise control ECU) communicate with one another to control the system based on some designation information. If the designation information of the hybrid vehicle control ECU and distance control ECU is different or distance control ECU is malfunctioning, this DTC is recorded.

DTC TROUBLE DETECTION CHART

The skid control ECU sends signals such as cruise control cancel demand signals, brake operation demand response signals from the hybrid vehicle control ECU, etc. to the hybrid vehicle control ECU when the dynamic laser cruise control system is in operation.

DTC TROUBLE DETECTION CHART

The hybrid vehicle control ECU sends signals such as dynamic laser cruise control operation signals, brake operation demand signals and buzzer operation demand signals, etc. to the skid control ECU when the dynamic laser cruise control is in operation. The hybrid vehicle control ECU is the only component that has a function to record and output the DTCs in the dynamic laser cruise control system. Therefore, if the skid control ECU detects a communication error from the hybrid vehicle control ECU, it sends the malfunction signal back to the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

The skid control ECU sends signals such as cruise control cancel demand signals, brake operation demand response signals from the hybrid vehicle control ECU, etc. to the hybrid vehicle control ECU when the dynamic laser cruise control system is in operation.

DTC TROUBLE DETECTION CHART

This circuit detects the yaw rate of the vehicle and transmits its signal to the skid control ECU and distance control ECU (cruise control ECU).

DTC TROUBLE DETECTION CHART

This circuit detects the angle and direction of the steering wheel and automatically transmits a signal to the skid control ECU and distance control ECU (cruise control ECU).

DTC TROUBLE DETECTION CHART

The laser sensor and distance control ECU transmit the data for general vehicle control and diagnosis function along the communication line. The laser sensor transmits information about the vehicle in front to the distance control ECU.

DTC TROUBLE DETECTION CHART

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The hybrid vehicle control ECU receives signals from each sensor and ECU, then sends signals such as the cruise control operation signal, brake control operation signal and laser light emission prohibiting signal, etc. to the distance control ECU. The hybrid vehicle control ECU sends signals such as dynamic laser cruise control operation signals, brake operation demand signals and buzzer operation demand signals, etc. to the skid control ECU when the dynamic laser cruise control is in operation. The hybrid vehicle control ECU is the only component that has a function to record and output the DTCs in the dynamic laser cruise control system. Therefore, if the distance control ECU and/or the skid control ECU detect a communication error from the hybrid vehicle control ECU, they send the malfunction signal back to the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

The distance control ECU (cruise control ECU) receives information about the area in front of the vehicle from the laser sensor and then sends a brake control demand signal (deceleration demand) and diagnosis signals, such as laser sensor grime signals or laser sensor malfunction signals, to the hybrid vehicle control ECU.

DTC TROUBLE DETECTION CHART

The laser sensor and distance control ECU transmit the data for general vehicle control and diagnosis function along the communication line. The distance control ECU determines the curve radius information based on signals from the steering wheel and yaw rate sensor. The distance control ECU transmits the current vehicle speed and curve radius information to the laser sensor.

DTC TROUBLE DETECTION CHART

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The cruise control main switch operates 8 functions: SET, COAST, TAP-DOWN, RESUME, ACCEL, TAP-UP, CANCEL and MODE. The SET, TAP-DOWN and COAST functions, and the RESUME, TAP-UP and ACCEL functions are operated with the same switch. The cruise control main switch is an automatic return type switch which turns on only while operating it in each arrow direction and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. The hybrid vehicle control ECU then reads the resistance value that has been changed by the switch operation to control MODE, SET, COAST, RESUME, ACCEL and CANCEL. The dynamic laser cruise control system has two cruise control modes: the constant speed control mode and vehicle-to-vehicle distance control mode.

1. The vehicle-to-vehicle distance control mode is always selected when starting up the dynamic laser cruise control system.
2. The operation of the constant speed control mode is the same as that for a conventional cruise control system.

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1. READ VALUE OF INTELLIGENT TESTER Connect the intelligent tester to the DLC3. Turn the ignition switch to the ON position, and turn the intelligent tester main switch on. Check the DATA LIST for proper functioning of the cruise control main switch. LASER CRUISE: TESTER DISPLAY DIAGNOSTIC CHART Tester Display Measurement Item/Range Normal Condition Diagnostic Note MAIN SW (MAIN) Main switch signal (Main CPU) / ON or OFF ON: Main switch ON (Pushed on) OFF: Main switch OFF (Pushed off) - CANCEL SW CANCEL switch signal / ON or OFF ON: CANCEL switch ON OFF: CANCEL switch OFF - SET/COAST SW -/SET switch signal / ON or OFF ON: -/SET switch ON OFF: -/SET switch OFF - RES/ACC SW +/RES switch signal / ON or OFF ON: +/RES switch ON OFF: +/RES switch OFF - OK: When cruise control main switch operation is performed, the result will be same as above. Result: RESULT REFERENCE Result Proceed to OK A NG (all items are defective) B NG (one to four items are defective) C A: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE C: REPLACE CRUISE CONTROL MAIN SWITCH B: Go to next step
2. INSPECT CRUISE CONTROL MAIN SWITCH Disconnect the cruise control main switch connector. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Switch Condition Specified Condition 1 - 2,1 - 3 Neutral 10 kohms or higher 1 - 3 +/RES 235 to 245 ohms 1 - 3 -/SET 620 to 640 ohms 1 - 3 CANCEL 1510 to 1570 ohms 1 - 3 Main Switch ON Below 1 ohms 1 - 2 MODE Below 1 ohms NG: REPLACE CRUISE CONTROL MAIN SWITCH OK: Go to next step
3. INSPECT SPIRAL CABLE NOTE: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may cause airbag deployment. Be sure to read the page shown in the brackets. HINT: Removal (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Installation (See «INSTALLATION»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Remove the spiral cable. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Condition Spiral Cable Position Specified Condition A-1 - C13-7 Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right A-3 - C13-1 Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right A-4 - C13-2 Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right HINT: The spiral cable makes a maximum of approximately 5 rotations. NG: REPLACE SPIRAL CABLE OK: Go to next step
4. CHECK WIRE HARNESS (SPIRAL CABLE - HYBRID VEHICLE CONTROL ECU) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition C13-1 - H29-26 (CCS) Always Below 1 ohms C13-7 - H29-18 (CCHG) Always Below 1 ohms C13-1 - Body ground Always 10 kohms or higher C13-7 - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. CHECK WIRE HARNESS (SPIRAL CABLE - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition C13-2 - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE HYBRID VEHICLE CONTROL ECU

This circuit provides power to operate the distance control ECU (cruise control ECU). The distance control ECU determines information about the vehicle in front based on data from the laser sensor, and then decides how much acceleration and/or deceleration is needed to maintain the set distance. The distance control ECU also requests the skid control ECU to apply braking and sound the buzzer.

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1. CHECK DISTANCE CONTROL ECU Disconnect the distance control ECU connector. Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition D2-1 (+B) - Body ground Ignition switch on 10 to 14 V Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition D2-10 (SGND) - Body ground Always Below 1 ohms D2-12 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

The distance control switch sets the vehicle-to-vehicle distance mode. The distance control switch is installed in the steering pad switch. The vehicle-to-vehicle distance set value can be changed by operating the steering pad switch (distance control switch) while the dynamic laser cruise control system is in operation. The steering pad switch uses the BEAN to communicate with each ECU. Therefore, it does not have a direct connection with the hybrid vehicle control ECU. If there are any malfunction in the communications line of the steering pad switch, one or more DTCs in the multiplex communication system are output.

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1. INSPECT STEERING PAD SWITCH ASSEMBLY Remove the steering pad switch assembly. Measure the resistance between terminal 4 (DIST) and (ECC) of steering pad switch assembly connector when distance control switch is operated. Standard resistance SWITCH POSITION REFERENCE Switch position Specified value Distance control switch is ON Below 1 ohms Distance control switch is OFF 10 kohms or higher HINT: When a malfunction is detected in the distance control switch, replace the steering pad switch assembly. NG: REPLACE STEERING PAD SWITCH ASSEMBLY OK: Go to next step
2. INSPECT SPIRAL CABLE NOTE: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may cause airbag deployment. Be sure to read the page shown in the brackets. HINT: Removal (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Installation (See «INSTALLATION»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) ) Remove the spiral cable. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Condition Spiral Cable Position Specified Condition A-4 - C13-11 Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right A-6 - C13-2 Center Below 1 ohms 2.5 rotations to the left 2.5 rotations to the right HINT: The spiral cable makes a maximum of approximately 5 rotations. NG: REPLACE SPIRAL CABLE OK: Go to next step
3. CHECK WIRE HARNESS (DISTANCE CONTROL ECU - SPIRAL CABLE) Disconnect the distance control ECU connector. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition C13-11 - D2-16 (MODE) Always Below 1 ohms D2-16 (MODE) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK WIRE HARNESS (SPIRAL CABLE - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition C13-2 - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
5. INSPECT DISTANCE CONTROL ECU Remove the distance control ECU (cruise control ECU) with the connector. Turn the ignition switch to the ON position. Measure the voltage according to the value(s) in the table below. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition D2-16 (MODE) - Body ground Distance control switch ON 0 to 2 V D2-16 (MODE) - Body ground Distance control switch OFF 9 to 16 V NG: REPLACE DISTANCE CONTROL ECU OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

This circuit provides power to operate the laser sensor. The laser sensor emits laser beams towards an object in front and measures the distance and direction of the object by receiving the beam reflections. Based on the reflections, the sensor calculates the difference in speed between your own vehicle and the object in front. This data is transmitted to the distance control ECU (cruise control ECU).

HINT

The laser sensor monitors the laser emission and reception by itself. This DTC is detected when it cannot monitor.

When rain drops or snowflakes strike the laser sensor face, the distance between the vehicle in front and your own vehicle cannot be measured correctly.

The dynamic laser cruise control system may not be able to detect the vehicle in front and may not properly maintain the correct vehicle-to-vehicle distance.

1. The vehicle in front is a tall trailer.
2. The back of the vehicle in front is extremely dirty.
3. Emissions from the vehicle in other lanes are heavy.
4. The vehicle in front has no reflector.
5. The laser sensor is receiving a strong flash of light (sunlight, etc.).

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1. CHECK DISTANCE CONTROL ECU (IGB VOLTAGE) Disconnect the L1 sensor connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition L1-5 (IGB) - Body ground Ignition switch on 10 to 16 V NG: GO TO step 3 OK: Go to next step
2. CHECK WIRE HARNESS (LASER SENSOR - HYBRID CONTROL ECU AND BODY GROUND) Disconnect the L1 sensor connector. Disconnect the H29 hybrid vehicle control ECU connector. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition H29-11 (LGND) - L1-1 (LGND) Below 1 ohms H29-11 (LGND) - Body ground 10 kohms or higher L1-2 (SGND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3. CHECK WIRE HARNESS (LASER SENSOR - DISTANCE CONTROL ECU) Disconnect the L1 sensor connector. Disconnect the D2 ECU connector. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Specified Condition L1-5 (IGB) - D2-13 (IGB) Below 1 ohms D2-13 (IGB) - Body ground 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

When the distance control ECU (cruise control ECU) detects that the wipers are operating, the dynamic laser cruise control system will be canceled.

HINT

A wiper switch signal is sent to the distance control ECU via the CAN and BEAN. If there are any malfunctions in this circuit, check for DTCs in the CAN communication and multiplex communication systems. When the wiper is in the HI mode, the dynamic laser cruise control is automatically canceled and goes into the standby mode.

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When the cruise control main switch is on, CRUISE main indicator light comes on. This indicates the control condition (presence or absence of a vehicle in front, vehicle-to-vehicle distance, and set vehicle speed) and fail-safe state through the multiplex communication system and CAN communication system. The master warning light and CRUISE main indicator light come on and vehicle-to-vehicle distance information is displayed on the combination meter as the alarm buzzer sounds. Items such as "CLEAN RADAR SENSOR", "CRUISE NOT AVAILABLE", "CHECK CRUISE SYSTEM" and "RADAR READY" are displayed in the multi-information display on the combination meter when the hybrid vehicle control ECU detects signals from each sensor and actuator and sends them to the combination meter via CAN and BEAN.

HINT

If the vehicle in front in the same lane significantly decreases vehicle speed or another vehicle pulls in front of your vehicle, adequate deceleration cannot be applied and the vehicle-to-vehicle distance will shorten. At this time, the system sounds the buzzer and the master warning light blinks to warn the driver. Each indicator in the dynamic laser cruise control uses CAN and BEAN for communication. Therefore if there are any malfunctions in this circuit, check for DTCs in the CAN communication and multiplex communication systems before troubleshooting this circuit.

Connecting terminals TC and CG of the DLC3 causes the system to enter self-diagnostic mode. If a malfunction is present, DTCs will be output.

HINT

When a particular warning light remains blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in the relevant ECU is suspected.

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1. CHECK WIRE HARNESS (TC of DLC3 - HYBRID VEHICLE CONTROL ECU) Disconnect the D1 connector from the DLC3 and H29 connector from the hybrid vehicle control ECU. Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition H29-3 (TC) - D1-13 (TC) Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - HYBRID VEHICLE CONTROL ECU) OK: Go to next step
2. CHECK WIRE HARNESS (CG of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition D1-4 (CG) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - BODY GROUND) OK: Go to next step
3. CHECK WIRE HARNESS (TC of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. Standard resistance TESTER CONNECTION SPECIFIED CONDITION Tester Connection Condition Specified Condition D1-13 (TC) - Body ground Always 10 kohms or higher NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU OK: REPLACE HYBRID VEHICLE CONTROL ECU

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1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL CAUTION: Wait for 90 seconds after disconnecting the cable to prevent the airbag working. (See «AIRBAG SYSTEM»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) )
2. REMOVE STEERING WHEEL NO.3 COVER LOWER (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) )
3. REMOVE STEERING WHEEL NO.2 COVER LOWER (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) )
4. REMOVE STEERING PAD (See «REMOVAL»(/lexus/rx/ii-2006-2009/remont/airbag/#supplemental-restraint-system) )
5. REMOVE CRUISE CONTROL MAIN SWITCH Disconnect the connector. Remove the 2 screws. Pull the cruise control main switch in the arrow direction to remove it.

See also:
• DTC P0705-757 Transmission Range Sensor Circuit; DTC P0705-758 Transmission Range Sensor Circuit; DTC P0851-775 Park / Neutral Switch Input Circuit Low
• REMOVAL
• REMOVAL
• REMOVAL