Active Torque Control 4WD System (Diagnostics - Introduction): Diagnosis Lexus RX III

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use the following procedure listed to troubleshoot the Active Torque Control 4WD system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. INSPECT BATTERY VOLTAGE Standard voltage 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step. NEXT: Go to next step
3. CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* Use the Techstream to check if the CAN communication system is functioning normally. Check for DTCs. Refer to «DIAGNOSIS SYSTEM»(ref-400834-S42883997332011051800000) . Result Result Proceed to CAN DTC is not output A CAN DTC is output B B --> Go to «CAN COMMUNICATION SYSTEM»(ref-400834-S02948345852011051800000) CAN COMMUNICATION SYSTEM A: Go to next step
4. CHECK DTC* Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-400849-S17754683082011051800000) . Clear the DTCs. Recheck for DTCs. Result Result Proceed to DTC does not reoccur A DTC does reoccur B B --> GO TO 7 STEP 7 A: Go to next step
5. PROBLEM SYMPTOMS TABLE Result Result Proceed to Fault not listed in problem symptoms table A Fault listed in problem symptoms table B B --> GO TO 7 STEP 7 A: Go to next step
6. OVERALL ANALYSIS AND TROUBLESHOOTING* Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-400849-S33654807122011051800000) . Data List / Active Test. Refer to «DATA LIST / ACTIVE TEST»(ref-400849-S07893540572011051800000) . NEXT: Go to next step
7. REPAIR OR REPLACE NEXT: Go to next step
8. CONFIRMATION TEST NEXT --> END

HINT

1. Use the following procedure listed to troubleshoot the Active Torque Control 4WD system.
2. *: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. INSPECT BATTERY VOLTAGE Standard voltage 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step. NEXT: Go to next step
3. CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM* Use the Techstream to check if the CAN communication system is functioning normally. Check for DTCs. Refer to «DIAGNOSIS SYSTEM»(ref-400834-S01955420032011051800000) . Result Result Proceed to CAN DTC is not output A CAN DTC is output B B --> Go to «CAN COMMUNICATION SYSTEM»(ref-400834-S02948345852011051800000) CAN COMMUNICATION SYSTEM A: Go to next step
4. CHECK DTC* Check for DTCs. Refer to «DTC CHECK / CLEAR»(ref-400849-S20937018322011051800000) . Clear the DTCs. Recheck for DTCs. Result Result Proceed to DTC does not reoccur A DTC does reoccur B B --> GO TO 7 STEP 7 A: Go to next step
5. PROBLEM SYMPTOMS TABLE Result Result Proceed to Fault not listed in problem symptoms table A Fault listed in problem symptoms table B B --> GO TO 7 STEP 7 A: Go to next step
6. OVERALL ANALYSIS AND TROUBLESHOOTING* Terminals of ECU. Refer to «TERMINALS OF ECU»(ref-400849-S33654807122011051800000) . Data List / Active Test. Refer to «DATA LIST / ACTIVE TEST»(ref-400849-S07893540572011051800000) . NEXT: Go to next step
7. REPAIR OR REPLACE NEXT: Go to next step
8. CONFIRMATION TEST NEXT --> END

TEST MODE PROCEDURE

1. DESCRIPTION HINT: When using a chassis dynamometer, brake tester, etc. to perform a vehicle test, activate test mode to avoid a "different tire diameter installed" incorrect judgment. Test mode does not have a 4WD parameter. Test mode is activated because it will prohibit a different tire diameter judgment. Control Status 4WD Control Status During test mode Different tire diameter malfunction judgment (detection that tire diameter of 4 wheels are not same) is not performed. Other than above item, normal control is performed. - 4 wheel drive control switch OFF (AWD auto mode status)- 4 wheel drive control switch ON (AWD lock mode status)
2. ACTIVATE TEST MODE HINT: Activate test mode before using a chassis dynamometer, brake tester, etc. to perform a vehicle test. Check that the engine switch is off. Use the following methods to change the 4WD ECU to test mode. Test mode activation by shorting TS terminal With the engine switch off, connect the TS and CG terminals of the DLC3 connector. Then turn the engine switch on (IG) to activate test mode. HINT: When the engine switch is on (IG) and the 4WD lock switch is turned from OFF to ON, the 4WD lock indicator blinks twice and then illuminates. NOTE: If a part of the 4WD system has a defect, the Master warning light will illuminate. Check if the combination meter has changed to the test mode display. Start the engine.
3. CONFIRM MODE CHANGE HINT: Operate the 4 wheel drive control switch (AWD lock switch), and check that the 4WD control mode changes. 4 Wheel Drive Control Switch Status AWD Lock Indicator Status AWD Control Status OFF Turns off AWD auto mode ON Illuminates 4WD lock mode Switch changed from OFF to ON Blinks twice, then illuminates At moment of illumination, changes to AWD lock mode

PROBLEM SYMPTOMS TABLE

HINT

1. Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
2. Inspect the fuses and relays related to this system before inspecting the suspected areas below.

ACTIVE TORQUE CONTROL 4WD SYSTEM

HINT

*: Tight corner braking phenomenon: a phenomenon in which a AWD vehicle may lurch and decelerate due to a rotational speed difference between the front and rear wheels, such as during low-speed cornering in AWD mode.

HINT

1. Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
2. Inspect the fuses and relays related to this system before inspecting the suspected areas below.

ACTIVE TORQUE CONTROL 4WD SYSTEM

HINT

*: Tight corner braking phenomenon: a phenomenon in which a AWD vehicle may lurch and decelerate due to a rotational speed difference between the front and rear wheels, such as during low-speed cornering in AWD mode.

Scheme 112

Scheme 113

1. CHECK 4WD ECU Measure the voltage and resistance of the connector. Terminal No. (Symbol) Terminal Description Condition Specified Condition 7 (4WDL) - Body ground 4 wheel drive control switch signal Engine switch on (IG) and Press continuously 4 wheel drive control switch ON Below 1 V 14 (CANH) - 16 (CANL) CAN communication Engine switch off 54 to 69 ohms 23 (GND) - Body ground Ground Engine switch off Below 1 ohms 11 (IG1) - 23 (GND) Power source voltage Engine switch on (IG) 10 to 14 V 13 (SLC+) - 32 (SLC-) 4WD linear solenoid signal D position, Idling Pulse generation ( (Scheme 113)waveform 1) 9 (BSLC) - 23 (GND) Power source voltage Always 10 to 14 V If the result is not as specified, the 4WD ECU may have a malfunction. Using an oscilloscope, check the waveform 1. WAVEFORM 1 (REFERENCE) Terminal Name Content Tester Range 5 V/DIV., 1 msec./DIV. Condition D position, Idling

Scheme 114

1. DESCRIPTION Active torque control 4WD system data can be read in the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs. Therefore when there seems to be a problem with the active torque control 4WD, use the Techstream or SST to check and troubleshoot it.
2. CHECK DATA LINK CONNECTOR 3 (DLC3) Check the DLC3. Refer to «GENERAL INFORMATION»(ref-400649-S41373024542011051800000)
3. WARNING LIGHT Furthermore, the master warning light in the combination meter assembly will illuminate and a warning message will be displayed on the multi-information display to inform the driver. Condition Master Warning Light Multi-information Display AWD system malfunction Illuminates CHECK AWD SYSTEM

DTC CHECK / CLEAR

1. CHECK DTC Check the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Read the DTCs following the prompts on the Techstream screen. Enter the following menus: Chassis / 4WD / Trouble Codes. Check the details of the DTCs. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-400849-S05755464632011051800000) .
2. CLEAR DTC Clear the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Operate the Techstream to clear the codes. Enter the following menus: Chassis / 4WD / Trouble Codes. According to the display on the Techstream, select the trouble code data display with the clear button.

1. CHECK DTC Check the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Read the DTCs following the prompts on the Techstream screen. Enter the following menus: Chassis / 4WD / Trouble Codes. Check the details of the DTCs. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-400849-S21149897682011051800000) .
2. CLEAR DTC Clear the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Turn the Techstream on. Operate the Techstream to clear the codes. Enter the following menus: Chassis / 4WD / Trouble Codes. According to the display on the Techstream, select the trouble code data display with the clear button.

DATA LIST / ACTIVE TEST

HINT

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

Note. In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

1. DATA LIST OF 4WD CONTROL ECU Connect the Techstream to the DLC3. Turn the engine switch on (IG). Following the display on the Techstream, select "Data List". Tester Display Measurement Item/Range Normal Condition Diagnostic Note 4WD Warning Light Master Warning Light and Multi-information Display/ OFF or ON OFF: Master warning light and Multi-information display off ON: Master warning light and Multi-information display on - Stop Light SW Stop Light Switch / OFF or ON OFF: Brake pedal released ON: Brake pedal depressed - Forward and Rearward G Deceleration sensor (Forward and Rearward G) / Min.: -25.10 m/s 2 Max.: 24.90 m/s 2 Approximately 0 +/-0.13 while stationary - FR Wheel Speed FR Wheel Speed / Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Almost no difference from the speedometer FL Wheel Speed FL Wheel Speed / Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Almost no difference from the speedometer RR Wheel Speed RR Wheel Speed / Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Almost no difference from the speedometer RL Wheel Speed RL Wheel Speed / Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Min.: 0 mph (0 km/h), Max.: 202 mph (326.4 km/h) Almost no difference from the speedometer SLC Solenoid Current SLC Solenoid (transfer control solenoid) Current / Min.: 0 A Max.: 3 A Min.: 0 A Max.: 3 A - Number of DTC Number of DTCs / 0 to 255 0 to 255
2. ACTIVE TEST OF 4WD CONTROL 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 engine switch on (IG). Following the display on the Techstream, select "Active Test". Tester Display Test Part Control Range Diagnostic Note 4WD Warning Light Master Warning Light and Multi-information Display ON: Master warning light and Multi-information display on OFF: Master warning light and Multi-information display off Observe combination meter

DIAGNOSTIC TROUBLE CODE CHART

ACTIVE TORQUE CONTROL 4WD SYSTEM

ACTIVE TORQUE CONTROL 4WD SYSTEM