P0300critical severityPowertrain

Random/Multiple Cylinder Misfire Detected

on 2009-2012 Audi Q5 3.2L V6 · AWD

What this code means

The PCM has detected misfires occurring in multiple cylinders randomly. This is different from a single-cylinder misfire and often points to a system-wide issue.

Symptoms

  • Check Engine Light (flashing if severe)
  • Rough idle
  • Vibration
  • Loss of power
  • Hesitation
  • Poor fuel economy
  • Possible catalyst damage

Common causes

  • Vacuum leak
  • Low fuel pressure
  • Faulty spark plugs (all)
  • Ignition coil pack failure
  • EGR valve stuck open
  • Low compression (multiple cylinders)
  • Wiring harness issue
  • MAF sensor problem

Diagnostic steps

  1. Check for vacuum leaks (smoke test)
  2. Test fuel pressure
  3. Inspect spark plugs
  4. Test ignition coils
  5. Check fuel injectors
  6. Test compression
  7. Check MAF sensor
  8. Monitor fuel trim values

Repair notes

Start with spark plugs and vacuum leaks. Flashing CEL means severe misfire - stop driving to protect catalytic converter.

Other Powertrain codes on this vehicle

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