Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
Vehicle » Testing and Inspection » Initial Inspection and Diagnostic Overview » Diagnostic Theory  
  Diagnostic Theory  

The shortest route to an accurate diagnosis results from:

  • system knowledge, including comparison with a known good system.
  • system history, including repair history and usage patterns.
  • condition history, especially any relationship to repairs or sudden change.
  • knowledge of possible sources.
  • using a systematic diagnostic method that divides the system into related areas.

The diagnosis and correction of noise, vibration and harshness concerns requires:

  • a road or system test to determine the exact nature of the concern.
  • an analysis of the possible causes.
  • testing to verify the cause.
  • repairing any concerns found.
  • a road test or system test to make sure the concern has been corrected or brought back to within an acceptable range