Abs & Traction Control System -- Diagnosis: Pre-Check

Diagnosis System
1. Check the indicator. When the ignition switch is turned ON, check that the ABS warning light, TRAC OFF indicator light and SLIP indicator light come on for 3 seconds.
  NOTE: If the indicator check result is not normal, proceed to the troubleshooting for the ABS WARNING LIGHT CIRCUIT , TRAC OFF INDICATOR LIGHT CIRCUIT and SLIP INDICATOR LIGHT CIRCUIT .
  
  Fig 1: Locating ABS Warning Light, TRAC OFF Indicator Light & SLIP Indicator Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. In case of not using LEXUS hand-held tester:
  1. Check the DTC.
    1. Disconnect the short pin from the DLC1.
    2. Using SST (SST 09843-18020 or 09843-18040), connect terminals Tc and E₁ of the DLC1, or terminals Tc and CG of the DLC3.
    3. Turn the ignition switch ON.
    4. Read the DTC from the ABS warning light and TRAC OFF indicator light on the combination meter.
      NOTE:
      
      If no code appears, inspect the diagnostic circuit, ABS WARNING LIGHT CIRCUIT , TRAC OFF INDICATOR, TRAC CUT SWITCH CIRCUIT or SLIP INDICATOR LIGHT CIRCUIT .
      
      As an example, the blinking patterns of the normal code and codes 11 and 21 are shown in Fig 4.
    5. Codes are explained in the DTC TROUBLE DETECTION TABLE .
    6. After completing the check, disconnect terminals Tc and E₁ of the DLC1, or terminals 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 1st.
3. In case of using LEXUS hand-held tester:
  1. Check the DTC.
    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.
      NOTE: Please refer to the LEXUS hand-held tester operator's manual for further details.
4. In case of not using LEXUS hand-held tester:
  1. Clear the DTC.
    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 and remove the short pin from DLC1.
    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 of the DLC1 or DLC3.
5. Connect the short pin to the DLC1.
  NOTE: The DTC stored in the ECU will be erased when the battery terminal is disconnected for the troubleshooting.
  
  Fig 7: Connecting Short Pin To DLC1
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. In case of using LEXUS hand-held tester:
  1. Clear the DTC.
    1. Hook up 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 LEXUS hand-held tester operator's manual).

Speed Sensor Signal Check

In case of not using LEXUS hand-held tester:
1. Check the speed sensor signal.
  1. Turn the ignition switch OFF.
  2. Using SST (SST 09843-18020 or 09843-18040), connect terminals Ts and E₁ of the DLC1 or terminals Ts and CG of the DLC3.
  3. Start the engine.
  4. Check that the ABS warning light blinks.
    NOTE: If the ABS warning light does not blink, inspect the ABS WARNING LIGHT CIRCUIT .
  5. Drive the vehicle straight forward. Drive the vehicle faster than 45 km/h (28 mph) for several seconds.
  6. Stop the vehicle.
  7. Using SST (SST 09843-18020 or 09843-18040), connect terminals Tc and E₁ of the DLC1, or terminals Tc and CG of the DLC3.
  8. Read the number of blinks of the ABS warning light.
    NOTE:
    See the list of DTC list shown in SPEED SENSOR DIAGNOSTIC TROUBLE CODES .
    
    If every sensor is normal, the 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.
  9. 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 terminals Ts and CG, Tc and CG of the DLC3, and turn the ignition switch OFF.

In case of using LEXUS hand-held tester:

Check the speed sensor signal.

Connect the LEXUS hand-held tester to the DLC3.
Do step 3 to step 6 under "In case of not using LEXUS hand-held tester".
Read the DTC by following the prompts on the tester screen. Please refer to the LEXUS hand-held tester operator's manual for further details.

SPEED SENSOR DIAGNOSTIC TROUBLE CODES

Code No.	Diagnosis	Trouble Area
C1271/71	Low output voltage of right front speed sensor	Right front speed sensor Sensor installation Right front speed sensor rotor
C1272/72	Low output voltage of left front speed sensor	Left front speed sensor Sensor installation Left front speed sensor rotor
C1273/73	Low output voltage of right rear speed sensor	Right rear speed sensor Sensor installation Right rear speed sensor rotor
C1274/74	Low output voltage of left rear speed sensor	Left rear speed sensor Sensor installation Left rear speed sensor rotor
C1275/75	Abnormal change in output voltage of right front speed sensor	Right front speed sensor rotor
C1276/76	Abnormal change in output voltage of left front speed sensor	Left front speed sensor rotor
C1277/77	Abnormal change in output voltage of right rear speed sensor	Right rear speed sensor rotor
C1278/78	Abnormal change in output voltage of left rear speed sensor	Left rear speed sensor rotor