ANTI-LOCK BRAKE SYSTEM CHECK FOR INTERMITTENT PROBLEMS

CHECK FOR INTERMITTENT PROBLEMS

1. Turn the ignition switch off.

2. Connect the GTS to the DLC3.

3. Turn the ignition switch to ON.

4. Turn the GTS on.

5. Follow the directions on the GTS to display the Data List and select areas where momentary interruptions should be monitored.

   Tip:
   

   • A momentary interruption (open circuit) cannot be detected for 3 seconds after the ignition switch is turned to ON (initial check).

   • If the Error display remains displayed, measure the resistance between the ECUs and sensors, or between ECUs.

   • The Error display on the GTS will remain displayed for 1 second after the harness signal changes from momentary interruption (open circuit) to the normal condition.

   
   
   1. Chassis > ABS/VSC/TRC > Data List

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      FR Speed Open	Front speed sensor RH open detection	Error or Normal	Normal	Error: Momentary interruption
      FL Speed Open	Front speed sensor LH open detection	Error or Normal	Normal	Error: Momentary interruption
      RR Speed Open	Rear speed sensor RH open detection	Error or Normal	Normal	Error: Momentary interruption
      RL Speed Open	Rear speed sensor LH open detection	Error or Normal	Normal	Error: Momentary interruption
      EFI Communication Open	ECM communication open detection	Error or Normal	Normal	Error: Momentary interruption
      Deceleration Open	Deceleration sensor open detection	Error or Normal	Normal	Error: Momentary interruption for 4WD and Pre-Runner
      IG Voltage Value Decreased	IG voltage value decrease detection	Error or Normal	Normal	Error: Voltage low
      IG Voltage Value Increased	IG voltage value increase detection	Error or Normal	Normal	Error: Voltage high
      FR Speed Sensor Voltage Open	Front speed sensor RH voltage open detection	Error or Normal	Normal	Error: Momentary interruption
      FL Speed Sensor Voltage Open	Front speed sensor LH voltage open detection	Error or Normal	Normal	Error: Momentary interruption
      RR Speed Sensor Voltage Open	Rear speed sensor RH voltage open detection	Error or Normal	Normal	Error: Momentary interruption
      RL Speed Sensor Voltage Open	Rear speed sensor LH voltage open detection	Error or Normal	Normal	Error: Momentary interruption
      EFI Communication Invalid	ECM communication invalid detection	Error or Normal	Normal	Error: Invalid

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6. While observing the screen, gently jiggle the connector or wire harness between the ECU and sensors, or between ECUs.

   OK
   Normal is displayed.

   Tip:

   If the display changes, the connector and/or the wire harness has caused a momentary interruption of the circuit. Repair or replace the connector and/or wire harness as one of them is faulty.