Page 377 of 4323
A21377
Engine Room J/B:
Fuel Pump
Relay
B17414
E6ECM Connector
FPR
± DIAGNOSTICSENGINE
DI±183
377 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check for open and short in harness and connector between fuel pump relay
and ECM.
PREPARATION:
(a) Remove the fuel pump relay from the engine room J/B.
(b) Disconnect the E6 ECM connector.
CHECK:
Measure the resistance between wire harness side connectors.
OK:
Standard:
Tester ConnectionSpecified Condition
Engine Room J/B (Fuel pump relay ter-
minal 1) ± FPR (E6±30)Below 1 W
Engine Room J/B (Fuel pump relay ter-
minal 1) or FPR (E6±30) ±
Body ground
10 kW or higher
NG Repair or replace harness or connector.
OK
Replace ECM (See page SF±80).
Page 378 of 4323

DI±184
± DIAGNOSTICSENGINE
378 Author: Date:
2005 SEQUOIA (RM1146U)
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.
DID85±01
Page 379 of 4323

A20646
20 V
/Division Injector Signal Waveform
20 V
/Division
GND
100 msec./Division (Idling)(Magnification)
GND
1 msec./Division (Idling)
Injection duration
± DIAGNOSTICSENGINE
DI±185
379 Author: Date:
2005 SEQUOIA (RM1146U)DTC No.
DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected
Open or short in engine wire
Connector connection
Vacuum hose connection
P0301
P0302
P0303
P0304
P0305
P0306
P0307
P0308
Misfiring of each cylinder is detected
Vacuum hose connection
Ignition system
Injector
Fuel pressure
Mass air flow meter
Engine coolant temperature sensor
Compression pressure
Valve clearance
Valve timing
PCV piping
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.
Page 380 of 4323

Crankshaft position sensor
(36±2 teeth or 12 teeth) Camshaft position sensor
ECM
A20490
DI±186
± DIAGNOSTICSENGINE
380 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
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:
Within 200 engine revolutions at a high rpm, the threshold for ºpercentage of misfire causing catalyst
damageº is reached 1 time.
Within 200 engine revolutions at a normal rpm, the threshold for ºpercentage of misfire causing catalyst
damageº is reached 3 time.
MONITOR STRATEGY
P0300Random/Multiple cylinder misfire detected
P0301Cylinder 1 misfire detected
P0302Cylinder 2 misfire detected
P0303Cylinder 3 misfire detected
Related DTCsP0304Cylinder 4 misfire detectedRelated DTCs
P0305Cylinder 5 misfire detected
P0306Cylinder 6 misfire detected
P0307Cylinder 7 misfire detected
P0308Cylinder 8 misfire detected
Rid / t
Main sensors/componentsCamshaft position sensor, Crankshaft position
sensor
Required sensors/components
Related sensors/componentsEngine coolant temperature sensor, Intake air
temperature sensor, Throttle position sensor
Frequency of operationContinuous
DurationEvery 1,000 revolutions (soon after engine is started: 1 time, other: 4 times) (emission related misfire)
Every 200 revolutions (1 or 3 times) (catalyst deteriorating misfire)
MIL operation2 driving cycles MIL ON
Immediate MIL blinking (Catalyst deteriorating misfire)
Sequence of operationNone
Page 381 of 4323

± DIAGNOSTICSENGINE
DI±187
381 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage8 V±
Throttle position learningCompleted
VVT systemNormal operate by scan±tool
Engine RPM400 to 5,700rpm
All of the following conditions are met:Condition 1 and 2
1. Engine coolant temperature±10C (14F)±
2. Either of the following conditions is met:Condition (a) or (b)
(a) Engine coolant temperature at engine
start±7C (19F)±
(b) Engine coolant temperature20C (68F)±
Fuel±cutOFF
Emission±related±misfire:
First 1,000 revolutions after engine start,
or check modeCrankshaft 1,000 revolutions
Except aboveCrankshaft 1,000 revolutions x 4
Catalyst±damage±misfire (MIL blinks):
All of the following conditions 1, 2 and 3
are metCrankshaft 200 revolutions
1. Driving cycle1st
2. Check modeOFF
3. Engine RPM±2,800 rpm
Except aboveCrankshaft 200 revolutions x 3
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Emission±related±misfire:
Misfire rate:1.2 % or more
Catalyst±damage±misfire (MIL blinks):
Number of misfire per 200 revolutions93 or more
(varies with intake air amount and RPM)
Multiple cylinders misfireDetected
MONITOR RESULT
Refer to page DI±26 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 ºConfirmation Monitorº).
MID (Monitor Identification Data) is assigned to each emissions±related component.
TID (Test Identification Data) is assigned to each test value.
Scaling is used to calculate the test value indicated on generic OBD ll scan tools.
Page 382 of 4323

DI±188
± DIAGNOSTICSENGINE
382 Author: Date:
2005 SEQUOIA (RM1146U)
Misfire monitor ± All cylinders
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A1$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A1$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 1
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A2$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A2$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 2
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A3$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A3$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 3
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A4$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A4$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 4
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A5$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A5$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 5
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A6$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A6$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 6
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A7$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A7$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Page 383 of 4323
± DIAGNOSTICSENGINE
DI±189
383 Author: Date:
2005 SEQUOIA (RM1146U)
Misfire monitor ± Cylinder 7
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A8$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A8$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Misfire monitor ± Cylinder 8
MIDTIDScalingDescription of Test ValueMinimum Test LimitMaximum Test Limit
$A9$0BMultiply by 1
(time)Exponential Weighted Moving Average
misfire counts for last 10 driving cycles
± total
065535
$A9$0CMultiply by 1
(time)Misfire counts for last and current driv-
ing cycles ± total065535
Page 384 of 4323

A15466A19380
Battery I18
Ignition SW
1
#80 #60 #40#20
#70#50ECM
#30 #10
6
2
I10 Injector No.2
I12 Injector No.4
I13 Injector No.5
I14 Injector No.6
I15 Injector No.7
I16 Injector No.8
7
1
2
12
1
2 1
2
1
2
2
2
2 3 2
5
7 4
I9 Injector No.1
1C
2D1
B
F10
Fusible Link BlockIGN2
Engine Room J/B
54
B2C1 1C
1J 1D 2
3
W±R6
AM2Instrument Panel J/B
W±R3
B±R
1
1
1
I11 Injector No.3
IG413
E8 E6
E6
E8 E6 E6
E6 E6
R±W B±R
B±R
B±R
B±R
B±R
B±R
B±RY R±B
L±R W
L G R
B±R B±R B±R
5
IG2
AM2
B±R
B±R
B±R
B±R
B±R
DI±190
± DIAGNOSTICSENGINE
384 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Refer to DTC P0351 on page DI±221 for the wiring diagram of the ignition system.
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±44).
(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.