Diagnostic Aids

Using scan tool, read MISFIRE CUR # display for each cylinder. This will help locate and isolate which cylinder misfire is affecting. Check secondary ignition wires. Check for damaged or faulty ignition coil. Substitute a known-good ignition coil. Check system grounds. Check air induction system, fuel pressure, injectors, and EGR valve. Excessive engine vibration could cause DTC to set. FAILURE RECORDS data can be used in determining vehicle mileage since DTC was last set and may help to learn how often condition occurs.