Diagnostic Aids

The current weak cylinder display on Tech 1 will indicate the location of a misfire correctly only if a single cylinder is misfiring. If more than one cylinder is suspect, monitor Tech 1 MISFIRE CYL screen. Then continue with diagnostic chart step 2), diagnosing cylinders which were displayed as misfiring.

Fig 1: Code P0300 Schematic (Regal) Misfire Detected

Fig 2: Code P0300 Flow Chart (Regal) Misfire Detected