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).
- When the Coolant Temp in the freeze frame data is less than 75锟斤拷C (167锟斤拷F), the misfires have occurred only while the engine is
being warmed up.
- An extremely imbalanced drive wheel which causes body vibration may cause misfire DTCs detection.
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO MISFIRE CODES)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
HINT
If any DTCs other than P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 are output, troubleshoot those DTCs first.
B -- GO TO DTC CHART See: Diagnostic Trouble Code Descriptions/SFI System
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (MISFIRE RPM AND MISFIRE LOAD)
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