P03792
± DIAGNOSTICSENGINE
DI±67
2001 PRIUS (RM778U)
(f) Turn ignition switch OFF and wait at least 5 seconds.
INSPECTION PROCEDURE
HINT:
If is the case that DTC besides misfire is memorized simultaneously, first perform the troubleshooting
for them.
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
data records the engine conditions when the malfunction is detected, when troubleshooting it is useful
for determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.
When the vehicle is brought to the workshop and the misfire is not occurred, misfire can be confirmed
by reproducing the condition or freeze frame data. Also, after finishing the repair, confirm that there
is no misfire. (See the confirmation driving pattern)
When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data
is besides the range of ±20%, there is a possibility that the air±fuel ratio is inclining either to ºrichº
(±20% or less) or ºleanº (+20% or more).
When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility or
misfire only during warming up.
In the case that misfire cannot be reproduced, the reason may be because of the driving with lack or
fuel, the use of improper fuel, a stain of ignition plug, and etc.
1 Check wire harness, connector and vacuum hose in engine room.
CHECK:
(a) Check the connection conditions of wire harness and connector.
(b) Check the disconnection, piping and break of vacuum hose.
NG Repair or replace, then confirm that there is no
misfire. (See the confirmation driving pattern)
OK
2 Check spark plug and spark of misfiring cylinder.
PREPARATION:
Remove the spark plug (See page IG±1).
CHECK:
(a) Check for carbon deposits on electrode.
(b) Check electrode gap.
OK:
(a) No large carbon deposit present.
Not wet with gasoline or oil.
(b) Electrode gap: 1.0 ± 1.2 mm (0.039 ± 0.047 in.)
PREPARATION:
(a) Install the spark plug to ignition coil and connect the igni-
tion coil connector to ignition coil.
