± DIAGNOSTICSENGINE
DI±191
385 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:
In order to memorize the DTC of misfire, it is necessary to drive around MISFIRE RPM, MISFIRE LOAD in
the DATA LIST for the following period of time. Take care not to turn the ignition switch OFF. Turning the
ignition switch OFF switches the diagnosis system from check mode to normal mode, and all DTCs, etc.,
are erased.
Engine SpeedTime
Idling3 minutes 30 seconds or more
1,000 rpm3 minutes or more
2,000 rpm1 minute 30 seconds or more
3,000 rpm1 minute or more
(f) Check if there is misfire, and the DTC and the freeze frame data. Record the DTC's, freeze frame data
and misfire counter data.
(g) Turn the ignition switch OFF and wait for at least 5 seconds.
INSPECTION PROCEDURE
HINT:
If DTCs besides misfire DTCs are memorized simultaneously, troubleshoot the non±misfire DTCs first.
If the misfire does not occur when the vehicle is brought to the workshop, the misfire can be confirmed
by reproducing the condition of the freeze frame data. Also, after finishing the repair, confirm that there
is no misfire (See confirmation driving pattern).
On 6 or 8 cylinder engines, misfiring cylinder identification is disabled at high engine speed and only
a general misfire fault code P0300 is stored instead of a cylinder specific misfire fault code (P0301 to
P0308).
If the misfire starts in a high engine speed area or the misfire occurs only in a high engine speed area,
only code P0300 may be stored.
When only a general misfire fault code like P0300 is stored:
Erase the general misfire fault code using the hand±held tester
Start the engine and drive the confirmation patten.
Read the value of the misfire ratio for each cylinder. Or read the DTC.
Repair the cylinder that has a high misfire ratio. Or repair the cylinder indicated by the DTC.
After finishing repairs, drive the confirmation pattern again and confirm that no misfire occurs.
When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data
is over the range of ±20 %, there is a possibility that the air±fuel ratio is becoming RICH (±20 % or
less) or LEAN (+20 % or more).
When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility of
misfire only during engine warm±up.
If the misfire cannot be reproduced, the following reasons may apply: 1) the vehicle has low fuel, 2)
improper fuel is being used, or 3) the ignition plug is contaminated.
Be sure to check the value on the misfire counter after the repair.
