Starting: Other Lexus ES XV40

PRECAUTION

Note. Some systems need to be initialized after reconnecting the negative (-) battery terminal (See INITIALIZATION ).

1. EMERGENCY ENGINE START CONTROL If there is a malfunction in the stop light switch or STOP fuse, their signals may not be correctly transmitted to the main body ECU. This may result in the engine not starting even if the engine switch is pressed while the brake pedal is depressed and the shift lever is in the P position. To activate the starter: Turn the engine switch from off to on (ACC). Press and hold the engine switch for 15 seconds.
2. PRECAUTIONS FOR PUSH-BUTTON START FUNCTION: Before starting the engine, firmly depress the brake pedal until the indicator in the engine switch turns green. The power source mode (off, on (ACC), on (IG)) is always retained in memory by the vehicle. If the battery is disconnected, the power source mode that was present before disconnection will be restored after the battery is reconnected. Be sure to turn the engine switch off before disconnecting the cable from the negative battery terminal. Be careful if the power source mode of a vehicle with a discharged battery is not known. After the battery is reconnected, be sure to wait 10 seconds or more before attempting to start the engine. The engine may not start immediately after the battery is reconnected. If the electrical key is held near the engine switch to start the engine when the electrical key battery is depleted, the following warnings will sound: Driver's door open --> closed An exit warning will sound if the shift lever is in a position other than P and the power source is in a mode other than off. An exit warning will sound if the shift lever is in the P position and the power source is in a mode other than off. Doors other than the driver door open --> closed A warning will sound to indicate that the electrical key has been taken out of the vehicle. These warnings will sound because it is not possible for the vehicle to determine if the key is present in the vehicle (due to the depleted key battery). These warnings do not indicate system malfunctions.

Scheme 137

Scheme 138

Scheme 139

Scheme 140

Communication table

COMMUNICATION TABLE

COMMUNICATION TABLE

Scheme 141

Scheme 142

Scheme 143

1. PUSH-BUTTON START FUNCTION DESCRIPTION The push-button start function uses a push-type engine switch, which the driver can operate by merely carrying the electrical key. This system consists primarily of the main body ECU, engine switch, ID code box, steering lock ECU, electrical key, ACC relay, IG1 relay, IG2 relay and certification ECU. The main body ECU controls the function. This function operates in cooperation with the smart access system with push-button start.
2. FUNCTION OF COMPONENT FUNCTION OF COMPONENT Component Function Engine Switch Transponder Key Amplifier Transponder engine switch signal to main body ECU. Informs driver of power source mode or system abnormality with illumination of indicator light. Receives ID code and transmits it to certification ECU when key battery is low. Electrical Key Receives signals from oscillators and returns ID code to door control receiver. Electrical Key Oscillator Console and Rear Seat Receives request signals from certification ECU and forms detection area in vehicle interior. Steering Lock ECU Receives lock/unlock request signals from certification ECU and main body ECU. Door Control Receiver Receives ID code from electrical key and transmits it to certification ECU. Main body ECU Changes power source mode in 4 stages (off, on (ACC), on (IG), start) in accordance with shift position and state of stop light switch. Controls push-button start function in accordance with signals received from switches and each ECU. Certification ECU Certifies ID code received from door control receiver and transmits certification results to ID code box and steering lock ECU. Stop Light Switch Outputs state of brake pedal to main body ECU. ID Code Box Receives steering unlock or engine immobilizer unset signals from certification ECU, certifies them, and transmits each unset signal to steering lock ECU or ECM. ECM Receives engine start request signal from main body ECU, turns ON ST relay, and starts engine. Receives signal from ID code box and performs engine ignition and injection.
3. SYSTEM FUNCTION The electric controls of the push-button start function are described below: ELECTRIC CONTROLS OUTLINE Control Outline Engine switch control When driver operates engine switch with electrical key in driver's possession, certification ECU starts indoor electrical key oscillator, which transmits request signal to electrical key. Upon receiving this signal, the electrical key transmits ID code signal to main body ECU. ID code box verifies check results received from certification ECU via LIN and sends them to main body ECU. Based on these results, main body ECU authorizes operation of engine switch. Diagnosis When main body ECU detects malfunction, main body ECU diagnoses and memorizes failed section.
4. CONSTRUCTION AND OPERATION Engine Switch The engine switch consists of a momentary type switch, 3 color (amber, green, greenish white) LEDs, and a transponder key amplifier. The greenish white LED is for illumination. The amber and green LEDs are for the indicator lights. The driver can check the present power source mode and whether the engine can start in accordance with the illumination state of the indicator light. When the main body ECU detects an abnormality in the push-button start function, it makes the amber indicator light flash. If the engine stopped in this state, it may not be possible to restart it. Indicator Light Condition Engine switch indicator light condition: ENGINE SWITCH INDICATOR LIGHT CONDITION Power Source Mode/Condition Indicator Light Condition Brake pedal released Brake pedal depressed, shift lever in P or N off OFF ON (Green) (When key and vehicle IDs match) on (ACC, IG) ON (Amber) ON (Green) ENGINE SWITCH INDICATOR LIGHT CONDITION Power Source Mode/Condition Indicator Light Condition Brake pedal released Brake pedal depressed, shift lever in P or N Engine running OFF OFF Steering lock not unlocked Flashes (Green) for 15 sec. Flashes (Green) for 15 sec. System malfunction Flashes (Amber) for 15 sec. Flashes (Amber) for 15 sec. Main body ECU The main body ECU consists of the IG1 and IG2 relay actuation circuits and CPU. HINT: Before removing the battery, make sure to turn the engine switch off. The main body ECU constantly stores the present power source mode in its memory. Therefore, if the main body ECU is interrupted by disconnecting the battery, the main body ECU restores the power source mode after the battery is reconnected. For this reason, if the battery is disconnected when the engine switch is not off, the power will be restored to the vehicle at the same time the power is restored to the main body ECU (by reconnecting the battery). After a new main body ECU is installed and the battery is reconnected, the power source mode will default to the engine switch on (IG) mode.
5. PUSH-BUTTON START FUNCTION OPERATION This system has different power source mode patterns depending on the brake pedal condition and shift lever position. POWER SOURCE MODE PATTERN AND BRAKE PEDAL CONDITION REFERENCE Brake Pedal Shift Lever Power Source Mode Pattern Depressed P or N position When the engine switch is pushed once. off --> engine start on (ACC) --> engine start on (IG) --> engine start Not depressed P position Each time the engine switch is pushed. off --> on (ACC) --> on (IG) --> off Except P position Each time the engine switch is pushed. off --> on (ACC) --> on (IG) --> on (ACC) - P position When the engine switch is pushed with power source mode on (IG) (engine running). on (IG) --> off - Except P position When the engine switch is pushed with power source mode on (IG) (engine running). on (IG) --> on (ACC) When the battery of the key is low, the push-button start function can be operated by holding the key against the engine switch. After approximately 1 hour has passed with the engine switch on (ACC) and the shift position in P, the main body ECU will automatically cut the power supply (the power source mode changes to off). The illustration below shows the transition of power source modes. Transition of power source mode: HINT: While the vehicle is being driven normally, operation of the engine switch is disabled. However, if the engine must be stopped in an emergency while the vehicle is being driven, pressing the engine switch for 3 seconds or more stops the engine. Power source mode changes from start to on (ACC).
6. WHEN KEY BATTERY IS LOW To operate the push-button start function when the key battery is low, hold the key close to the engine switch with the brake pedal depressed. The main body ECU transmits a key verification request signal from the stop light switch to the certification ECU. The certification ECU does not receive an ID code response from the door control receiver, so it actuates the transponder key amplifier built into the engine switch. The transponder key amplifier outputs an engine immobilizer radio wave to the key. The key receives the radio wave, and returns a radio wave response to the transponder key amplifier. The transponder key amplifier combines the key ID codes with the radio wave response, and transmits it to the certification ECU. The certification ECU judges and verifies the ID code, and transmits a key verification OK signal to the main body ECU. The buzzer in the combination meter sounds at the same time. After the buzzer sounds, if the engine switch is pressed within 5 seconds with the brake pedal not depressed, the power source mode changes to on (ACC) or on (IG), the same as in the normal condition.
7. DIAGNOSIS The main body ECU can detect malfunctions in the push-button start function when the power source mode is on (IG). When the ECU detects a malfunction, the amber indicator light of the engine switch flashes to warn the driver. At the same time, the ECU stores a 5-digit DTC (Diagnostic Trouble Code) in the memory. The indicator light warning continues for 15 seconds even after the power source mode is changed to off. The DTC can be read by connecting the intelligent tester to the DLC3. The push-button start function cannot be operated if a malfunction occurs.