TOYOTA SEQUOIA 2001 Service Repair Manual

B17397
Vehicle Speed
Between
38 mph and 75 mph
(60 km/h and 120 km/h)
Idling
Ignition Switch OFF
3 to 5 minutes
Time 2 minutes
(a), (b), (c)(e)
(d)
± DIAGNOSTICSENGINE
DI±177
371 Author: Date:
2005 SEQUOIA (RM1146U)
15 Perform confirmation driving pattern.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and turn the tester ON.
(c) Clear DTCs (see page DI±43).
(d) Switch the ECM from normal mode to check mode using the tester (see page DI±44).
(e) Start the engine and warm it up with all the accessories switched OFF.
(f) Drive the vehicle at between 38 mph and 75 mph (60 km/h and 120 km/h) and at an engine speed of
between 1,400 rpm and 3,200 rpm for 3 to 5 minutes.
HINT:
If the system is still malfunctioning, the MIL will be illuminated during step (e).
NOTICE:
If the conditions in this test are not strictly followed, no malfunction will be detected.
NEXT
16 Check whether DTC output recurs (DTC P0171, P0172, P0174 or P0175)
CHECK:
(a) On the hand±held tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC
INFO / PENDING CODES.
(b) Read DTCs.
RESULT:
Display (DTC Output)Proceed To
P0171, P0172, P0174 or P0175A
No outputB
B Go to step 5.
A

DI±178
± DIAGNOSTICSENGINE
372 Author: Date:
2005 SEQUOIA (RM1146U)
END

A21043
Starter Relay EFI Relay
Circuit Opening
Relay
Fuel Pump RelayMREL
FPRTr2
Tr1 EFI No.1
IGNECM
FC
NE Fuel Pump
Battery
StarterFuel Pump Resistor
AM2Ignition Switch
STA
Crankshaft Position
Sensor (NE Signal)
± DIAGNOSTICSENGINE
DI±179
373 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0230 Fuel Pump Primary Circuit
CIRCUIT DESCRIPTION
In the diagram below, when the engine is cranked, current flows from terminal STAR of the ECM to the starter
relay coil and also current flows to terminal STA of the ECM (STA signal).
When the STA signal and NE signal are input to the ECM, the Tr1 is turned ON, current flows to the coil of
the circuit opening relay, the relay switches on, power is supplied to the fuel pump, and the fuel pump oper-
ates.
While the NE signal is generated (engine running), the ECM keeps the Tr1 ON (circuit opening relay ON)
and the fuel pump also keeps operating.
The fuel pump speed is controlled at two levels (high speed or low speed) by the condition of the engine
(starting, light load, heavy load). When the engine starts (STA ON), the Tr2 in the ECM is OFF, so the fuel
pump relay closes and battery positive voltage is applied directly to the fuel pump. The fuel pump operates
at high speed.
After the engine starts while idling or light loads, since the Tr2 goes ON, power is supplied to the fuel pump
via the fuel pump resistor. The fuel pump operates at low speed.
DICEW±02

DI±180
± DIAGNOSTICSENGINE
374 Author: Date:
2005 SEQUOIA (RM1146U)DTC No.
DTC Detecting ConditionTrouble Area
P0230Open or short in fuel pump relay circuit

Open or short in fuel pump relay circuit

Fuel pump relay

Circuit opening relay

Fuel pump

ECM

A23553
G±R
1 28
A 6
BECM
AM2
W±B6
32
15 3
2 121
3 2B IA1
J5
J/CL±O
I18
Ignition SW
3
7
F10
Fusible Link BlockB±R
BI530
10 26 4
12
2
114
68
1 41
5 3L±B
AM2
52HE6
2D
2F 1J1C2F
IA4
E4
E4 IG4
IA4 2H
2H 2C 1C
1JFPR
FC
MREL B±O5
J44
J45J/C E
L
BB1G±RG±REngine Room J/B
4
2F
5V V V
IL2
25
G±O G±O
B
IG2
W±B
W±BA
ED 5 4G±RIG1
B±WB±W
Instrument Panel J/B
F9
Fuel Pump
Resister
Battery2C
W±R W±R5
6
EFI No.15
C/OPN Relay Fuel Pump
Relay
EFI Relay F19
Fuel Pump
± DIAGNOSTICSENGINE
DI±181
375 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
HINT:
This diagnostic chart is based on premise that engine is started. If the engine is not started, proceed to prob-
lem symptoms table on DI±33.

B17411
E6E1
FPR
A21024
DI±182
± DIAGNOSTICSENGINE
376 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
1 Check voltage between terminal FPR and E1 of ECM.
CHECK:
Measure the voltage between terminals of E6 and E6 ECM con-
nectors.
OK:
Tester ConnectionConditionSpecified Condition
FPR (E6±30) ± E1 (E6±1)STA signal ON9 to 14 V
FPR (E6±30) ± E1 (E6±1)STA signal OFF0 to 3 V
OK Replace ECM (See page SF±80).
NG
2 Check fuel pump relay.
PREPARATION:
Remove the fuel pump relay from the engine room R/B.
CHECK:
Inspect the fuel pump relay.
OK:
Terminal No.ConditionSpecified Condition
3 ± 4Apply B+ between
terminals 1 and 210 KW or higher
3 ± 4AlwaysBelow 1 W
3 ± 5Always10 KW or higher
3 ± 5Apply B+ between
terminals 1 and 2Below 1 W
NG Replace fuel pump relay.
OK

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).

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

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.

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