
DI-605
DIAGNOSTICS - ENGINE (2UZ-FE)
DIDRH-01
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
DTC P0307 Cylinder 7 Misfire Detected
DTC P0308 Cylinder 8 Misfire Detected
CIRCUIT DESCRIPTION
When a misfire occurs in the engine, hydrocarbons (HC) enter the exhaust in high concentrations. If this HC
concentration is high enough, there could be an increase in exhaust emission levels. High concentrations
of HC can also cause the temperature of the catalyst to increase, possibly damaging the catalyst. To prevent
this increase in emissions and limit the possibility of thermal damage, the ECM monitors the misfire rate.
When the temperature of the catalyst reaches a point of thermal degradation, the ECM will blink the MIL.
For monitoring misfire, the ECM uses both the camshaft position sensor and the crankshaft position sensor.
The camshaft position sensor is used to identify misfiring cylinders and the crankshaft position sensor is used
to measure variations in the crankshaft rotation speed. The misfire counter increments when crankshaft rota-
tion speed variations exceed threshold values.
If the misfiring rate exceeds the threshold value, which could cause emissions deterioration, the ECM illumi-
nates the MIL.
DI-606
DIAGNOSTICS - ENGINE (2UZ-FE)
DTC No. DTC Detecting Condition Trouble Area
S Open or short in engine wire
P0300 Misfiring of random cylinders is detected S Connector connection
S Vacuum hose connection
S Ignition system
P0301 S Injector
P0302 S Fuel pressure
P0303 S Mass air flow meter
P0304 S Engine coolant temperature sensor
Misfiring of each cylinder is detected
P0305 S Compression pressure
P0306 S Valve clearance
P0307 S Valve timing
P0308 S PCV piping
S ECM
HINT:
When several codes for a misfiring cylinder are recorded repeatedly but no random misfire code is recorded,
it indicates that the misfires have been detected and recorded at different times.
Reference: Inspection using the oscilloscope.
With the engine idling, check the waveform between terminals #1 to #8 and E01 of the ECM connectors.
HINT:
The correct waveform is as shown in the illustration.
Injector Signal Waveform
(Magnification)
20 V 20 V
/Division /Division
GND GND
100 msec./Division (Idling) Injection duration 1 msec./Division (Idling)
A20646
DI-607
DIAGNOSTICS - ENGINE (2UZ-FE)
MONITOR DESCRIPTION
Camshaft position sensor
Crankshaft position sensor ECM
(36-2 teeth or 12 teeth)
A20490
The ECM illuminates the MIL (2 trip detection logic) if:
The ECM will illuminate the MIL when the percentage of misfire exceeds the specified limit per 1,000 engine
revolutions. One occurrence of excessive misfire during engine start will set the MIL. Four occurrences are
required to set the MIL 1,000 revolutions after engine start.
The ECM blinks the MIL (the MIL blinks immediately) if:
S Within 200 engine revolutions at a high rpm, the threshold for "percentage of misfire causing catalyst
damage" is reached 1 time.
S Within 200 engine revolutions at a normal rpm, the threshold for "percentage of misfire causing catalyst
damage" is reached 3 time.
MONITOR STRATEGY
P0300 Random/Multiple cylinder misfire detected
P0301 Cylinder 1 misfire detected
P0302 Cylinder 2 misfire detected
P0303 Cylinder 3 misfire detected
Related DTCs P0304 Cylinder 4 misfire detected
P0305 Cylinder 5 misfire detected
P0306 Cylinder 6 misfire detected
P0307 Cylinder 7 misfire detected
P0308 Cylinder 8 misfire detected
Camshaft position sensor, Crankshaft position
Main sensors/components
sensor
Required sensors/components
R i d / t
Engine coolant temperature sensor, Intake air
Related sensors/components
temperature sensor, Throttle position sensor
Frequency of operation Continuous
Every 1,000 revolutions (soon after engine is started: 1 time, other: 4 times) (emission related misfire)
Duration
Every 200 revolutions (1 or 3 times) (catalyst deteriorating misfire)
2 driving cycles: MIL ON
MIL operation
Immediate: MIL blinking (Catalyst deteriorating misfire)
Sequence of operation None
DI-608
DIAGNOSTICS - ENGINE (2UZ-FE)
TYPICAL ENABLING CONDITIONS
Specification
Item
It
Minimum Maximum
The monitor will run whenever this DTC is
See page DI-437
not present
Battery voltage 8V -
Throttle position learning Completed
VVT system Normal operate by scan tool
Engine RPM 400 rpm 5,700rpm
All of the following conditions are met: Condition 1 and 2
1. Engine coolant temperature -10_C (14_F) -
2. Either of the following conditions is met: Condition (a) or (b)
(a) Engine coolant temperature at engine
-7_C (19_F) -
start
(b) Engine coolant temperature 20_C (68_F) -
Fuel-cut OFF
Emission-related-misfire:
First 1,000 revolutions after engine start,
Crankshaft 1,000 revolutions
or check mode
Except above Crankshaft 1,000 revolutions x 4
Catalyst-damage-misfire (MIL blinks):
All of the following conditions 1, 2 and 3
Crankshaft 200 revolutions
are met
1. Driving cycle 1st
2. Check mode OFF
3. Engine RPM - 2,800 rpm
Except above Crankshaft 200 revolutions x 3
TYPICAL MALFUNCTION THRESHOLDS
Detection Criteria Threshold
Emission-related-misfire:
Misfire rate: 1.2 % or more
Catalyst-damage-misfire (MIL blinks):
93 or more
Number of misfire per 200 revolutions
(varies with intake air amount and RPM)
Multiple cylinders misfire Detected
MONITOR RESULT
Refer to page DI-445 for detailed information.
The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").
S MID (Monitor Identification Data) is assigned to each emissions-related component.
S TID (Test Identification Data) is assigned to each test value.
S Scaling is used to calculate the test value indicated on generic OBD ll scan tools.
DI-609
DIAGNOSTICS - ENGINE (2UZ-FE)
Misfire monitor - All cylinders
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A1 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A1 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 1
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A2 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A2 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 2
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A3 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A3 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 3
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A4 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A4 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 4
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A5 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A5 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 5
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A6 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A6 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 6
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A7 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A7 $0C 0 65535
(time) ing cycles - total
DI-610
DIAGNOSTICS - ENGINE (2UZ-FE)
Misfire monitor - Cylinder 7
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A8 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A8 $0C 0 65535
(time) ing cycles - total
Misfire monitor - Cylinder 8
MID TID Scaling Description of Test Value Minimum Test Limit Maximum Test Limit
Exponential Weighted Moving Average
Multiply by 1
$A9 $0B misfire counts for last 10 driving cycles 0 65535
(time)
- total
Multiply by 1 Misfire counts for last and current driv-
$A9 $0C 0 65535
(time) ing cycles - total
DI-611
DIAGNOSTICS - ENGINE (2UZ-FE)
WIRING DIAGRAM
Refer to DTC P0351 on page DI-642 for the wiring diagram of the ignition system.
Access Cab, Standard Cab:
I14 Injector No. 1 ECM
2
B-R R E5 #10
1 2
I15 Injector No. 2
B-R W 3
E5 #20
1 2
B-R I16 Injector No. 3
4
B-R G
E5 #30
1 2
B-R I17 Injector No. 4
5
B-R R-B
I23 E5 #40
1 2
Ignition SW Driver Side J/B B-R I18 Injector No. 5
4 7 5 6
B-R B-R IE1 B-R B-R L
1I 1J E5 #50
7 AM2 6 1 2
IG2
B-R I19 Injector No. 6
8 7
W-R B-R Y
IA9 2 E5 #60
1
Engine Room R/B B-R I20 Injector No. 7
W-R 3
B-R L-R
AM2 E7 #70
B 1 2 1 2
2 2 I21 Injector No. 8
2
B-R R-W
1 2 E7 #80
B-L (*1)
B (*2)
Battery
*1: Towing Package
*2: Except Towing Package
A23594
DI-612
DIAGNOSTICS - ENGINE (2UZ-FE)
Double Cab:
ECM
I14 Injector No. 1
2
B-R R E5 #10
1 2
I15 Injector No. 2
3
B-R W
E5 #20
1 2
B-R I16 Injector No. 3
4
B-R G
E5 #30
1 2
B-R I17 Injector No. 4
5
B-R R-B
I23 E5 #40
Driver Side J/B 1 2
Ignition SW B-R I18 Injector No. 5
2 IGN2 1 5 6
AM2 IG2 B-R
1C 1D B-R IE1 B-R B-R L E5 #50
5 6 1 2
I19 Injector No. 6
W-R B-R 7
B-R Y
E5 #60
3 1C 1 2
Driver B-R I20 Injector No. 7
3
Side B-R L-R
E7 #70
J/B 1 2
7 1J I21 Injector No. 8
2
B-R R-W
W-R E7 #80
1 2
1 2C
Engine
AM2
Room
J/B
1 2D
B
10
F13
FL
Block
12 B
Battery
A23595
DI-613
DIAGNOSTICS - ENGINE (2UZ-FE)
CONFIRMATION DRIVING PATTERN
(a) Connect the hand-held tester to the DLC3.
(b) Record DTC and the freeze frame data.
(c) Use the hand-held tester to set the check mode (See page DI-463).
(d) Read the value on the misfire counter for each cylinder when idling. If the value is displayed on the
misfire counter, skip the following procedure of confirmation driving.
(e) Drive the vehicle several times with the engine speed, load and surrounding range shown as ENGINE
SPD, CALC LOAD in the freeze frame data or MISFIRE RPM, MISFIRE LOAD in the DATA LIST.
If you have no hand-held tester, turn the ignition switch OFF after the symptom is simulated once. Then re-
peat the simulation process again.
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 Speed Time
Idling 3 minutes 30 seconds or more
1,000 rpm 3 minutes or more
2,000 rpm 1 minute 30 seconds or more
3,000 rpm 1 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:
S If DTCs besides misfire DTCs are memorized simultaneously, troubleshoot the non-misfire DTCs first.
S 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).
S 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:
S Erase the general misfire fault code using the hand-held tester
S Start the engine and drive the confirmation patten.
S Read the value of the misfire ratio for each cylinder. Or read the DTC.
S Repair the cylinder that has a high misfire ratio. Or repair the cylinder indicated by the DTC.
S After finishing repairs, drive the confirmation pattern again and confirm that no misfire occurs.
S 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