Vehicle Skid Control - Diagnosis: Pre-Check

1. Using SST (SST 09843-18020 or 09843-18040), connect terminals Tc and E₁ of the DLC1 or terminals Tc and CG of the DLC3.
2. Turn the ignition switch ON.
3. Read the DTC from the VSC warning light on the combination meter.
   NOTE:

   • If no code appears, inspect the TC TERMINAL CIRCUIT in Anti-Lock Brake System (Including With VSC) - Diagnosis - Lexus article or DTC ALWAYS ON: MALFUNCTION IN ECU VSC WARNING LIGHT CIRCUIT  .
   • As an example, the blinking patterns for the normal code and code 31 and 32 are shown in Fig 3 .
Fig 2: Identifying DLC1 & DLC3 Connector Terminals
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4. Codes are explained in the code table (see DIAGNOSTIC TROUBLE CODE CHART ).
5. After completing the check, disconnect terminals Tc and E₁ of the DLC1 or Tc and CG of the DLC3, and turn OFF the display.

If 2 or more malfunctions are indicated simultaneously, the lowest numbered DTC will be displayed first.

1. Connect the LEXUS hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. Read the DTC by following the prompts on the tester screen.

1. Using SST (SST 09843-18020 or 09843-18040), connect terminals Tc and E₁ of the DLC1 or Tc and CG of the DLC3.
2. Turn the ignition switch ON.
3. Clear the DTC stored in the ECU by depressing the brake pedal 8 or more times within 5 seconds.
4. Check that the warning light shows the normal code.
5. Remove the SST (SST 09843-18020 or 09843-18040) from the terminals of the DLC1 or the DLC3.

1. Connect the LEXUS hand-held tester to the DLC3.
2. Turn the ignition switch ON.
3. Operate the LEXUS hand-held tester to erase the codes. (See the LEXUS hand-held tester operator's manual.)

1. Turn the ignition switch OFF.
2. Check that the shift lever position is at P range, turn the steering wheel to the neutral position.
3. Using SST (SST 09843-18020 or 09843-18040), connect terminals Ts and E₁ of the DLC1 or terminals Ts and CG of the DLC3.
Fig 7: Identifying DLC1 & DLC3 Connector Terminals
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4. Start the engine.
5. Check that the VSC warning light blinks.
   NOTE: If the VSC warning light does not blink, inspect the DTC ALWAYS ON: MALFUNCTION IN ECU VSC WARNING LIGHT CIRCUIT  and TS TERMINAL CIRCUIT in Anti-Lock Brake System (Including With VSC) - Diagnosis - Lexus article .
6. After a new ECU installed, the first time only: Start the engine and keep the vehicle in the stationary condition on the flat place for 3 sec. or more, it's installed the zero point calibration of the yaw rate sensor.
7. Check the steering angle sensor. Turn the steering wheel to either left or right to the full lock position, from the vehicle stationary condition, and turn back the steering wheel to the neutral position.
Fig 8: VSC Warning Light Blinking Pattern
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8. Check the yaw rate sensor. Shift the shift lever to the D range and drive the vehicle at the vehicle speed of approx. 5 km/h (3 mph), turn the steering wheel either to left or right 90° or more, and maintain 180° circular drive for the vehicle. Stop the vehicle and shift the shift lever to the P range, check that the VSC buzzer sounds for 3 sec.
   NOTE:

   • If the VSC buzzer sounds, the sensor check is in normal completion.
   • If the VSC buzzer does not sound, do the sensor check again.
   • If the VSC buzzer still won't sound, there is a malfunction in the VSC sensor, so check the DTC.
   • Drive the vehicle in a 180° circle. At the end of the turn, the direction of the vehicle should be within 180° +/- 5° of its start position.
   • Do not spin the front wheels.
Fig 9: Checking Yaw Rate Sensor
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9. Using SST (SST 09843-18020 or 09843-18040), connect terminals Tc and E₁ of the DLC1 or terminals Tc and CG of the DLC3.
10. Read the number of blinks of the VSC warning light.
    NOTE:

    • See VSC SENSOR DIAGNOSTIC TROUBLE CODES  table.
    • If every sensor is normal, a normal code is output. (A cycle of 0.25 seconds ON and 0.25 seconds OFF is repeated.)
    • If 2 or more malfunctions are indicated simultaneously, the lowest numbered code will be displayed first.
Fig 10: Malfunction Code Blinking Pattern Example (DTC Codes 71 & 72)
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11. After doing the check, disconnect the SST (SST 09843-18020 or 09843-18040) from terminals Ts and E₁ , Tc and E₁ of the DLC1 or Ts and CG, Tc and CG of the DLC3 and turn the ignition switch OFF.

1. Connect the LEXUS hand-held tester to the DLC3.
2. Do steps  2 and  4 to  8 under "not using LEXUS hand-held tester".
3. Read the DTC by following the prompts on the tester screen.

Fig 11: Connecting LEXUS Hand-Held Tester To DLC3

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002