CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the Techstream on.
- Record the DTC(s) and freeze frame data.
- Using the Techstream, switch the ECM from normal mode to check mode See: Powertrain Management/Computers and Control
Systems/Testing and Inspection/Reading and Clearing Diagnostic Trouble Codes/Check Mode Procedure.
- Read the misfire counts of each cylinder (Cylinder #1 (to #6) Misfire Count) with the engine idling. If any misfire count is displayed, skip the
following confirmation driving pattern.
- Drive the vehicle several times with the conditions, such as engine speed and engine load, shown in Misfire RPM and Misfire Load in the Data
List.
HINT
In order to store misfire DTCs, it is necessary to operate the vehicle for the period of time shown in the table below, using the
Misfire RPM and Misfire Load in the Data List.
- Check whether misfires have occurred by checking DTCs and freeze frame data.
HINT
Do not turn the engine switch off until the stored DTC(s) and freeze frame data have been recorded. When the ECM returns to
normal mode (default), the stored DTC(s), freeze frame data and other data will be cleared.
- Record the DTC(s), freeze frame data and misfire counts.
- Turn the engine switch off and wait for at least 5 seconds.
INSPECTION PROCEDURE
HINT
- If any DTCs other than misfire DTCs are output, troubleshoot those DTCs first.
- Read freeze frame data using the Techstream. 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.
- 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:
* There was insufficient fuel volume in the tank.
* Improper fuel is used.
* The spark plugs have been contaminated.
- After finishing repairs, check the misfire counts of the cylinders (Cylinder #1 Misfire Count to Cylinder #6 Misfire Count).
- Be sure to confirm that no misfiring cylinder DTCs are set again by conducting the confirmation driving pattern after
finishing repairs.
- For 6 cylinder engine, the ECM intentionally does not set the specific misfiring cylinder DTCs at high engine speed. If misfires
occur only in high engine speed areas, only DTC P0300 is set.
- In the event of DTC P0300 being present, perform the following operations:
* Clear the DTCs See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Reading and
Clearing Diagnostic Trouble Codes/DTC Check / Clear.
* Start the engine and conduct the confirmation driving pattern.
* Read the misfiring rates of each cylinder or DTC(s) using the Techstream.
* Repair the cylinder(s) that has a high misfiring rate or is indicated by the DTC.
* After finishing repairs, conduct the confirmation driving pattern again, in order to verify that DTC P0300 is not set.
- When one of Short FT #1, Long FT #1, Short FT #2 or Long FT #2 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 more).
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