Dynamic Radar Cruise Control System (Diagnostic Codes & Circuit Tests): Overview Lexus RX III

DESCRIPTION

The dynamic radar cruise control system uses the same vehicle speed signal that is sent to the ECM for the SFI system. If DTC P0500 is detected, perform the diagnosis using the inspection procedure for DTC P0500 in the SFI system (for 2GR-FE). Refer to DTC P0500: Vehicle Speed Sensor "A" . The speed signal is converted for use by the cruise control inside the ECM. Both the SFI system and the dynamic radar cruise control system can set DTC P0500, however, the detection conditions of the two systems are different.

The dynamic radar cruise control system uses the same vehicle speed signal that is sent to the ECM for the SFI system. If DTC P0500 is detected, perform the diagnosis using the inspection procedure for DTC P0500 in the SFI system (for 2GR-FE). Refer to DTC P0500: Vehicle Speed Sensor "A" . The speed signal is converted for use by the cruise control inside the ECM. Both the SFI system and the dynamic radar cruise control system can set DTC P0500, however, the detection conditions of the two systems are different.

If a malfunction (a rapid change in vehicle speed) in the vehicle speed signal being output from the skid control ECU is detected while the cruise control is in operation, the ECM determines that there is a momentary interruption or noise, and outputs a DTC.

Scheme 79

If a malfunction (a rapid change in vehicle speed) in the vehicle speed signal being output from the skid control ECU is detected while the cruise control is in operation, the ECM determines that there is a momentary interruption or noise, and outputs a DTC.

1. When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM 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 ECM through the STOP fuse and the stop light switch, and the ECM turns the cruise control off.
2. The ECM receives the brake demand signal from the driving support ECU and transmits it to the skid control ECU. The skid control ECU receives a signal from the ECM and operates the brake actuator. The skid control ECU operates the brake actuator and at the same time illuminates the stop light by operating the stop light control relay.

Scheme 80

1. When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM 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 ECM through the STOP fuse and the stop light switch, and the ECM turns the cruise control off.
2. The ECM receives the brake demand signal from the driving support ECU and transmits it to the skid control ECU. The skid control ECU receives a signal from the ECM and operates the brake actuator. The skid control ECU operates the brake actuator and at the same time illuminates the stop light by operating the stop light control relay.

This DTC indicates a malfunction in the ECM.

HINT

The ECM 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.

This DTC indicates a malfunction in the ECM.

HINT

The ECM 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.

The millimeter wave radar sensor emits radar beams toward 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.

HINT

The millimeter wave radar sensor monitors the millimeter wave circuit activation by itself. This DTC is output when one of the following occurs: 1) the monitor is malfunctioning, 2) an EEPROM error is detected, 3) a voltage error is detected, and 4) the radar sensor is not adjusted. When raindrops or snowflakes strike the millimeter wave radar sensor face, the distance between the vehicle in front and your own vehicle cannot be measured correctly. The dynamic radar cruise control system functions by detecting the beam reflections from 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. There are heavy emissions from a vehicle in front or vehicles in other lanes.

The millimeter wave radar sensor emits radar beams toward 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.

HINT

The millimeter wave radar sensor monitors the millimeter wave circuit activation by itself. This DTC is output when one of the following occurs: 1) the monitor is malfunctioning, 2) an EEPROM error is detected, 3) a voltage error is detected, and 4) the radar sensor is not adjusted. When raindrops or snowflakes strike the millimeter wave radar sensor face, the distance between the vehicle in front and your own vehicle cannot be measured correctly. The dynamic radar cruise control system functions by detecting the beam reflections from 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. There are heavy emissions from a vehicle in front or vehicles in other lanes.

This DTC is output when the scanning angle of the millimeter wave radar sensor is incorrect. This DTC is also output when the millimeter wave radar sensor beam axis is determined to be in an incorrect position.

This DTC is output when the scanning angle of the millimeter wave radar sensor is incorrect. This DTC is also output when the millimeter wave radar sensor beam axis is determined to be in an incorrect position.

The skid control ECU receives an alarm demand signal from the driving support 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 decreasing.

HINT

If the vehicle ahead in the same lane significantly decreases its speed or another vehicle moves 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 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.

Scheme 81

The skid control ECU receives an alarm demand signal from the driving support 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 decreasing.

HINT

If the vehicle ahead in the same lane significantly decreases its speed or another vehicle moves 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 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.

HINT

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.

Scheme 82

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

HINT

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.

The driving support ECU (distance control ECU) and ECM always communicate the data for vehicle general control and diagnosis function each other through communication line.

The driving support ECU determines the distance, relative speed, and target deceleration speed based on the signal from the millimeter wave radar sensor, and it transmits a control demand signal to the ECM.

The driving support ECU (distance control ECU) and ECM always communicate the data for vehicle general control and diagnosis function each other through communication line.

The driving support ECU determines the distance, relative speed, and target deceleration speed based on the signal from the millimeter wave radar sensor, and it transmits a control demand signal to the ECM.

The ECM receives signals from each sensor and ECU, then sends signals such as A/T signals, cruise control operation signals, low speed operation signals, brake control operation signals, and radar light emission prohibiting signals, to the driving support ECU. The ECM is the only component that has a function to record and output the DTCs in the dynamic radar cruise control system. Therefore, if the driving support ECU detects a communication error from the ECM, it sends a malfunction signal back to the ECM.

The ECM receives signals from each sensor and ECU, then sends signals such as A/T signals, cruise control operation signals, low speed operation signals, brake control operation signals, and radar light emission prohibiting signals, to the driving support ECU. The ECM is the only component that has a function to record and output the DTCs in the dynamic radar cruise control system. Therefore, if the driving support ECU detects a communication error from the ECM, it sends a malfunction signal back to the ECM.

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

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

The skid control ECU (brake actuator assembly) sends signals such as cruise control cancel signals and brake demand response signals to the ECM when the dynamic radar cruise control system is in operation.

The skid control ECU (brake actuator assembly) sends signals such as cruise control cancel signals and brake demand response signals to the ECM when the dynamic radar cruise control system is in operation.

The ECM sends signals such as A/T information signals, dynamic radar cruise control operation signals, brake operation demand signals, and buzzer operation demand signals to the skid control ECU (brake actuator assembly) when the dynamic radar cruise control is in operation. The ECM is the only component that has a function to record and output the DTCs in the dynamic radar cruise control system. Therefore, if the skid control ECU detects a communication error from the ECM, it sends a malfunction signal back to the ECM.

The ECM sends signals such as A/T information signals, dynamic radar cruise control operation signals, brake operation demand signals, and buzzer operation demand signals to the skid control ECU (brake actuator assembly) when the dynamic radar cruise control is in operation. The ECM is the only component that has a function to record and output the DTCs in the dynamic radar cruise control system. Therefore, if the skid control ECU detects a communication error from the ECM, it sends a malfunction signal back to the ECM.

The ECM communicates several signals with each sensor and ECU by CAN communication circuit.

There are any malfunctions in the communication circuit, one or more DTCs in the CAN communication system are output.

The ECM communicates several signals with each sensor and ECU by CAN communication circuit.

There are any malfunctions in the communication circuit, one or more DTCs in the CAN communication system are output.

The millimeter wave radar sensor and driving support ECU transmit the data for general vehicle control and diagnosis function along the communication line. The millimeter wave radar sensor transmits information about the vehicle in front to the driving support ECU.

Scheme 83

The millimeter wave radar sensor and driving support ECU transmit the data for general vehicle control and diagnosis function along the communication line. The millimeter wave radar sensor transmits information about the vehicle in front to the driving support ECU.

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

Scheme 84

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

The cruise control main switch operates 8 functions: SET, -(COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP, CANCEL, and MODE. The SET, TAP-DOWN, and - (COAST) functions, and the RES (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 the direction of each arrow and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. The ECM then reads the voltage value that has been changed by the switch operation to control MODE, SET, - (COAST), RES (RESUME), + (ACCEL), and CANCEL. The dynamic radar 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 radar 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 USING TECHSTREAM Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Radar Cruise / Data List. Check the Data List for proper functioning of the cruise control main switch. TEXT IN ILLUSTRATION *1 ON-OFF *2 CANCEL *3 -SET *4 +RES *5 MODE RADAR CRUISE (ECM) Techstream Display Measurement Item/Range Normal Condition Diagnostic Note Main SW M-CPU Main switch signal (Main CPU)/ON or OFF ON: Main switch ON OFF: Main switch OFF - Cancel Switch CANCEL switch signal/ON or OFF ON: CANCEL switch ON OFF: CANCEL switch OFF - SET/COAST Switch SET/COAST switch signal/ON or OFF ON: - SET switch ON OFF: - SET switch OFF - RES/ACC Switch RES/ACC switch signal/ON or OFF ON: + RES switch ON OFF: + RES switch OFF - OK When the cruise control main switch is operated, the display changes as shown above. Result Result Proceed to OK A NG (all items are defective) B NG (1 to 3 items are defective) C C --> See step 8 B --> See step 2 A --> See step 7
2. INSPECT CRUISE CONTROL MAIN SWITCH Remove the cruise control main switch. Refer to «REMOVAL»(ref-400829-S40867737822011051800000) . TEXT IN ILLUSTRATION *1 Component without harness connected: (Cruise Control Main Switch) *2 ON-OFF *3 CANCEL *4 -SET *5 +RES *6 MODE Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition A-1 (ECC) - A-2 (R/N) A-1 (ECC) - A-3 (CCS) Main switch off*1 1 Mohms or higher A-1 (ECC) - A-3 (CCS) Main switch on Below 2.5 ohms A-1 (ECC) - A-2 (R/N) MODE Below 2.5 ohms A-1 (ECC) - A-3 (CCS) + RES 235 to 245 ohms A-1 (ECC) - A-3 (CCS) - SET 617 to 643 ohms A-1 (ECC) - A-3 (CCS) CANCEL 1509 to 1571 ohms *1: The lever is in the neutral position. Remove the cruise control main switch. Refer to «REMOVAL (TO 8/2009)»(ref-400829-S40867737822011051800000) . NG --> See step 8 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - CRUISE CONTROL MAIN SWITCH) Disconnect the cruise control switch wire connector from the spiral cable and cruise control main switch. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A-1 (ECC) - m1-4 (ECC) Always Below 1 ohms A-2 (R/N) - m1-1 (R/N) Always Below 1 ohms A-3 (CCS) - m1-3 (CCS) Always Below 1 ohms Reconnect the cruise control switch wire connector. TEXT IN ILLUSTRATION *1 Cruise control switch wire: (to Spiral Cable Sub-assembly) *2 Cruise control switch wire: (to Cruise Control Main Switch) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. INSPECT SPIRAL CABLE SUB-ASSEMBLY 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 article shown in the brackets. HINT: Removal. Refer to «REMOVAL»(ref-400651-S34517911102011051800000) Installation. Refer to «INSTALLATION»(ref-400651-S38674347252011051800000) Remove the spiral cable sub-assembly. Refer to «REMOVAL»(ref-400651-S34517911102011051800000) . TEXT IN ILLUSTRATION *1 Component without harness connected: (Spiral Cable Sub-assembly) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition m1-1 (R/N) - F40-7 (R/N) The spiral cable position is center Below 1 ohms The spiral cable position is 2.5 rotations to the left The spiral cable position is 2.5 rotations to the right m1-3 (CCS) - F40-1 (CCS) The spiral cable position is center Below 1 ohms The spiral cable position is 2.5 rotations to the left The spiral cable position is 2.5 rotations to the right m1-4 (ECC) - F40-2 (ECC) The spiral cable position is center Below 1 ohms The spiral cable position is 2.5 rotations to the left The spiral cable position is 2.5 rotations to the right HINT: The spiral cable makes a maximum of approximately 5 rotations. Install the spiral cable sub-assembly. Refer to «INSTALLATION»(ref-400651-S38674347252011051800000) . NG --> See step 9 OK: Go to next step
5. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - ECM, BODY GROUND) Disconnect the ECM connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F40-1 (CCS) - A43-45 (CCS) Always Below 1 ohms F40-7 (R/N) - A43-37 (CCHG) Always Below 1 ohms F40-1 (CCS) - Body ground Always 10 kohms or higher F40-7 (R/N) - Body ground Always 10 kohms or higher F40-2 (ECC) - Body ground Always Below 1 ohms Reconnect the ECM connector. TEXT IN ILLUSTRATION *1 Front view of wire harness connector: (to Spiral Cable Sub-assembly) *2 Front view of wire harness connector: (to ECM) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 6
6. REPLACE ECM. Refer to «REMOVAL (TO 8/2009)»(ref-400788-S26250166532011051800000)
7. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-400837-S05075927772011051800000)
8. REPLACE CRUISE CONTROL MAIN SWITCH. Refer to «REMOVAL (TO 8/2009)»(ref-400829-S40867737822011051800000)
9. REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to «REMOVAL»(ref-400651-S34517911102011051800000)

The cruise control main switch operates 8 functions: SET, -(COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP, CANCEL, and MODE. The SET, TAP-DOWN, and - (COAST) functions, and the RES (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 the direction of each arrow and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. The ECM then reads the voltage value that has been changed by the switch operation to control MODE, SET, - (COAST), RES (RESUME), + (ACCEL), and CANCEL. The dynamic radar 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 radar cruise control system.
2. The operation of the constant speed control mode is the same as that for a conventional cruise control system.

The distance control switch sets the vehicle-to-vehicle distance control 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 radar 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 ECM. If there are any malfunctions in the communication 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. Refer to «REMOVAL»(ref-400650-S27675387012011051800000) . Disconnect the z5 connector from the spiral cable. TEXT IN ILLUSTRATION *1 Component without harness connected (Steering Pad Switch Assembly) *2 Distance Control Switch Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition z5-4 (DIST) - z5-6 (ECC) Distance control switch ON Below 2.5 ohms z5-4 (DIST) - z5-6 (ECC) Distance control switch OFF 10 kohms or higher Remove the steering pad. Refer to «REMOVAL»(ref-400650-S27675387012011051800000) .. NG --> See step 6 OK: Go to next step
2. INSPECT SPIRAL CABLE SUB-ASSEMBLY 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 article shown in the brackets. HINT: Removal. Refer to «REMOVAL»(ref-400651-S34517911102011051800000) Installation. Refer to «INSTALLATION»(ref-400651-S38674347252011051800000) Remove the spiral cable sub-assembly. Refer to «REMOVAL»(ref-400651-S34517911102011051800000) . TEXT IN ILLUSTRATION *1 Component without harness connected (Spiral Cable Sub-assembly) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition z5-4 (DIST) - F40-11 (DIST) The spiral cable position is center Below 1 ohms The spiral cable position is 2.5 rotations to the left The spiral cable position is 2.5 rotations to the right z5-6 (ECC) - F40-2 (ECC) The spiral cable position is center Below 1 ohms The spiral cable position is 2.5 rotations to the left The spiral cable position is 2.5 rotations to the right HINT: The spiral cable makes a maximum of approximately 5 rotations. Install the spiral cable sub-assembly. Refer to «INSTALLATION»(ref-400651-S38674347252011051800000) . NG --> See step 7 OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - DRIVING SUPPORT ECU, BODY GROUND) Disconnect the driving support ECU connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition F40-11 (DIST) - C1-7 (MODE) Always Below 1 ohms F40-11 (DIST) - Body ground Always 10 kohms or higher F40-2 (ECC) - Body ground Always Below 1 ohms Reconnect the driving support ECU connector. TEXT IN ILLUSTRATION *1 Front view of wire harness connector (to Spiral Cable Sub-assembly) *2 Front view of wire harness connector (to Driving Support ECU) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. INSPECT DRIVING SUPPORT ECU Turn the engine switch on (IG). TEXT IN ILLUSTRATION *1 Component without harness connected (Driving Support ECU) Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition C1-7 (MODE) - Body ground Distance control switch ON 0 to 2 V Distance control switch OFF 11 to 14 V NG --> See step 8 OK --> See step 5
5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-400837-S05075927772011051800000)
6. REPLACE STEERING PAD SWITCH ASSEMBLY. Refer to «REMOVAL»(ref-400651-S01272841122011051800000) .
7. REPLACE SPIRAL CABLE SUB-ASSEMBLY. Refer to «REMOVAL»(ref-400651-S34517911102011051800000)
8. REPLACE DRIVING SUPPORT ECU. Refer to «REMOVAL (TO 08/2009)»(ref-400829-S19981220402011051800000)

The distance control switch sets the vehicle-to-vehicle distance control 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 radar 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 ECM. If there are any malfunctions in the communication line of the steering pad switch, one or more DTCs in the multiplex communication system are output.

When the cruise control main switch is turned on, the cruise main indicator light and "RADAR READY" indicator come 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 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 Cruise Ready" are displayed on the multi-information display on the combination meter when the ECM detects signals from each sensor and actuator and sends them to the combination meter via CAN.

HINT

If the vehicle in front in the same lane significantly decreases vehicle speed or another vehicle moves 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 radar cruise control uses CAN for communication. Therefore, if there are any malfunctions in this circuit, check for DTCs in the CAN communication system before troubleshooting this circuit.

When the cruise control main switch is turned on, the cruise main indicator light and "RADAR READY" indicator come 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 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 Cruise Ready" are displayed on the multi-information display on the combination meter when the ECM detects signals from each sensor and actuator and sends them to the combination meter via CAN.

HINT

If the vehicle in front in the same lane significantly decreases vehicle speed or another vehicle moves 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 radar cruise control uses CAN for communication. Therefore, if there are any malfunctions in this circuit, check for DTCs in the CAN communication system before troubleshooting this circuit.

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

Scheme 96

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

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

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 HARNESS AND CONNECTOR (TERMINAL TC of DLC3 - ECM) Disconnect the ECM connector. TEXT IN ILLUSTRATION *1 DLC3 *2 Front view of wire harness connector: (to ECM) Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A43-16 (TC) - F17-13 (TC) Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - ECM) OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (TERMINAL CG of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *1 DLC3 Standard Resistance Tester Connection Condition Specified Condition F17-4 (CG) - Body ground Always Below 1 ohms NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR (DLC3 - BODY GROUND) OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (TERMINAL TC of DLC3 - BODY GROUND) Measure the resistance according to the value(s) in the table below. TEXT IN ILLUSTRATION *1 DLC3 Standard Resistance Tester Connection Condition Specified Condition F17-13 (TC) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OR EACH ECU OK --> See step 4
4. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-400837-S05075927772011051800000)

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

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.