Four Wheel Drive Control System (Diagnostics - Introduction): Other Lexus IS II facelift 2

TERMINALS OF ECU [08/2012 - ]

HINT

Inspect the connector from the back side while the connector is connected.

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1. 4WD CONTROL ECU: Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition CANH (A32-14) - CANL (A32-16) B - V CAN communication line Engine switch off 54 to 67 ohms IG1 (A32-11) - GND (A32-23) B-W - W-B Power source voltage Engine switch on (IG) 10 to 14 V SLC+ (A32-13) - SLC- (A32-32) P-L - G-R Transfer control solenoid signal Engine switch on (IG) Pulse generation (see waveform 1) FREE (A32-2) - GND (A32-23) G - W-B Sets the center differential free Engine switch on (IG), open and short terminals OPA and CG of the DLC3. 10 to 14 V --> 0 to 1.5 V GND (A32-23) - Body ground W-B - Body ground Ground Always Below 1 ohms Waveform 1 (Reference): Item Contents Tool setting 5 V/DIV, 2 ms./DIV Vehicle condition Engine stop, Engine switch on (IG)

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1. DIAGNOSIS SYSTEM Inspect the battery voltage. Standard voltage 11 to 14 V If the voltage is below 11 V, recharge the battery before proceeding. Check the DLC3. The 4WD control ECU uses CAN and the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format. Verify the conditions listed in the table below. Symbols (Terminal No.) Terminal Description Condition Specified condition SIL (7) - SG (5) Bus "+" line During transmission Pulse generation CG (4) - Body ground Chassis ground Always Below 1 ohms SG (5) - Body ground Signal ground Always Below 1 ohms BAT (16) - Body ground Battery positive Always 11 to 14 V CANH (6) - CANL (14) HIGH-level CAN bus line Engine switch off 54 to 67 ohms CANH (6) - Battery positive HIGH-level CAN bus line Engine switch off 1 Mohms or higher CANH (6) - CG (4) HIGH-level CAN bus line Engine switch off 3 kohms or higher CANL (14) - Battery positive LOW-level CAN bus line Engine switch off 1 Mohms or higher CANL (14) - CG (4) LOW-level CAN bus line Engine switch off 3 kohms or higher HINT: If the display shows a communication error message when the cable of the Techstream is connected to the DLC3, the engine switch is turned on (IG) and the Techstream is operated, there is a problem on either the vehicle side or the tester side. If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle. If communication is still not possible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's operator's manual.
2. FUNCTION OF 4WD INDICATOR The 4WD indicator light in the combination meter assembly (multi-information display) warns the driver of abnormal or poor condition of the four wheel drive control system.
3. CHECK 4WD INDICATOR LIGHT Using SST, connect terminals TC and CG of the DLC3 (to enter the DTC output mode). SST: 09843-18040 Turn the engine switch on (IG). "DIAG" is displayed on the multi-information display, and the 4WD control ECU checks the system for malfunctions. If the 4WD control system is normal, "DIAG AWD OK" will be displayed on the multi-information display. If the 4WD control system is not normal, "DIAG AWD XX (DTC)" will be displayed on the multi-information display. Although the Test Mode is not set for the 4WD control system, the message shown in the illustration will be displayed on the multi-information display when the Test Mode is activated to check the VSC, etc. HINT: Test Mode DTCs will not be stored because the Test Mode is not set. On the multi-information display, VSC, TIRE PRESSURE and 4WD are displayed in order. If the systems above are not displayed on the multi-information display, there may be a malfunction in "TC and CG Terminal Circuit". Refer to «TC and CG Terminal Circuit»(ref-606544-S23264653352014032500000) . If the 4WD indicator light check result is not normal, proceed to troubleshooting for the 4WD indicator light circuit. Trouble Area See procedure 4WD indicator light (Remains on) Refer to «PROBLEM SYMPTOMS TABLE [08/2012 - ]»(ref-606543-S19713720202014032500000) 4WD indicator light (Does not come on)
4. FAIL-SAFE FUNCTION If following malfunctions occur, the 4WD control ECU will stop the function of 4WD control system or partly change the function to control the system. Malfunction Control Malfunction in a speed sensor Stop the function Malfunction in the steering angle sensor and throttle signal line Partly change the function

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1. DTC CHECK (Techstream) Check the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Check the DTCs by following the prompts on the tester screen. HINT: Refer to the Techstream operator's manual for further details. Clear the DTCs. Connect the Techstream to the DLC3. Turn the engine switch on (IG). Clear the DTCs by following the prompts on the tester screen. HINT: Refer to the Techstream operator's manual for further details.
2. DTC CHECK (SST CHECK WIRE) Check the DTCs. Using the SST, connect terminals TC and CG of the DLC3 (enter in the DTC output mode). SST: 09843-18040 Turn the engine switch on (IG). "DIAG" is displayed on the multi-information display, and the 4WD control ECU checks the system for malfunctions. If the 4WD control system is normal, "DIAG AWD OK" will be displayed on the multi-information display (normal system code). If the 4WD control system is not normal, "DIAG AWD XX (DTC)" will be displayed on the multi-information display. Clear the DTCs. Using SST, connect terminals TC and CG of the DLC3. SST: 09843-18040 Turn the engine switch on (IG). Clear the DTCs stored in the 4WD control ECU by depressing the brake pedal 8 times or more within 5 seconds. Check that the 4WD indicator light (multi-information display) indicated a "AWD OK". Turn the engine switch off. Remove the SST from the terminals of DLC3.