Caution / Notice / Hint

HINT: 

• In the past, when the primary ignition system (the igniter drive circuit in the ECM, the primary circuit in the ignition coil assembly, the related wire harness, or the connector) was out of order, diagnostic codes from P0351-13 to P0354-13 were output. However, these codes are not output in this vehicle.

  When a failure in the primary ignition system is suspected, refer to "Catalyst OT Misfire Fuel Cut History", "Catalyst OT Misfire Fuel Cut Cylinder #1 to #4", and "Misfire Count Cylinder #1 to #4" in the Freeze Frame Data, the pending Freeze Frame Data, and the Data List, and confirm in which cylinder the high-frequency misfire was concentrated.

• Referring to the following contents of the Freeze Frame Data (or the pending Freeze Frame Data) enables an estimation of which cylinder has misfired and to what degree.
  • Misfire Count Cylinder #1 to #4: Misfire count according to cylinder.
  • Catalyst OT Misfire Fuel Cut Cylinder #1 to #4: This expresses a high-frequency misfire was concentrated in a certain cylinder and that cylinder's fuel injection was stopped.
• If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
• If the misfire does not recur when the vehicle is brought to the workshop, reproduce the conditions stored in the ECM as Freeze Frame Data.
• If the misfire still cannot be reproduced even though the conditions stored in the ECM as Freeze Frame Data have been reproduced, one of the following factors is considered to be a possible cause of the problem:
  1. There was insufficient fuel in the tank.
  2. Improper fuel was used.
  3. The spark plugs have been contaminated.
  4. The problem requires further diagnosis.
• After finishing repairs, check the misfire counts of the cylinders (Misfire Count Cylinder #1 to Misfire Count Cylinder #4).
• Be sure to confirm that no misfiring cylinder DTCs are stored again by performing the confirmation driving pattern after finishing repairs.
• When one of Short FT B1S1, Long FT B1S1 in the Freeze Frame Data is outside the range of +/-20%, the air fuel ratio may be rich (-20% or less) or lean (+20% or higher).
• When Coolant Temperature in the Freeze Frame Data is less than 75°C (167°F), the misfires have occurred only while warming up the engine.
• Vehicle body vibration caused by an extremely imbalanced drive wheel may cause misfire DTCs to be stored.
• Read Freeze Frame Data using the GTS. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.