NOTES WITH REGARD TO DIAGNOSIS


1.
Phenomenon
 Explanation of phenomenon
When the engine starts, a knocking sound can be heard coming from the engine compartment.
 This sound occurs as a result of system operation checking, and is not a malfunction.

  • Sound of the motor inside the ABS hydraulic unit operation. (whine)
  • Sound is generated along with vibration of the brake pedal. (scraping)
  • When ABS operates, sound is generated from the vehicle chassis due to repeated brake application and release. (Thump: suspension; squeak: tyres)

 This is the sound of normal system operation, and is not a malfunction.
Shocks are felt if the brake pedal is depressed when driving at low speed.
 This is due to system operation checking (starting-of check when the vehicle speed reaches a certain number of km/h) and is not a malfunction.
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