2001 TOYOTA SEQUOIA fuel pressure

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.

DI±202
± DIAGNOSTICSENGINE
396 Author: Date:
2005 SEQUOIA (RM1146U)
16 Check fuel pressure (See page SF±7).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF±1).
OK
17 Check intake air temperature and mass air flow rate.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON.
CHECK:
Check the intake air temperature.
(1) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II /
DATA LIST / ALL / INTAKE AIR.
(2) Read its value displayed on the hand±held tester.
OK:
Equivalent to ambient temperature
CHECK:
Check the air flow rate.
(1) When using hand±held tester, enter the following menu: DIAGNOSIS/ENHANCED OBD II/DATA
LIST/ALL/MAF.
(2) Read its value displayed on the hand±held tester.
OK:
ConditionAir Flow Rate (gm/s)
Ignition switch ON (do not start engine)0
Idling4 to 6
Running without load (2,500 rpm)13 to 20
Idling to quickly acceleratingAir flow rate fluctuates
NG Replace mass air flow meter.
OK

B17440
A46
Air Switching Valve Connector Wire Harness Side:
± DIAGNOSTICSENGINE
DI±239
433 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:

Using the AIR INJ CHECK operation of the SYSTEM CHECK provided in the hand±held tester func-
tion, conditions for air±fuel ratio and pressure in the secondary air injection system passage can be
checked while the secondary air injection system operating. It helps technicians to troubleshoot the
system when it malfunctioning.

Read freeze frame data using a hand±held tester. Freeze frame data record the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle
was moving or stationary, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, and
other data, from the time the malfunction occurred.
1 Check voltage between terminal 1 of air switching valve connector and body
ground.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A46 air switching valve connector.
(c) Connect the hand±held tester to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
CHECK:
(a) When the air switching valve is operated using the hand±
held tester, measure voltage between terminal A46±1 of
the air switching valve connector and body ground.
(b) Select the following menu items: DIAGNOSIS/EN-
HANCED OBD II/SYSTEM CHECK/ AIR INJ CHECK/
MANUAL OPERATION/OPERATION 1 and 4
HINT:
OPERATION 1: AP:OFF, EASV:CLOSE, ASV1:CLOSE,
ASV2:CLOSE
OPERATION 4: AP:OFF, EASV:OPEN, ASV1:CLOSE,
ASV2:CLOSE
NOTICE:
This test only allows technicians to operate the AI system
for 5 seconds. Furthermore, the test can be performed 4
times a trip. If the test is repeated, intervals of at least 30
seconds are required between tests.
While the AI system operation using the hand±held tester
is prohibited, the tester displays the prohibition (WAIT or
ERROR). If the ERROR (AI STATUS NG) is displayed on the
tester, stop the engine for 10 minutes and then try again..
OK:
Standard:
Tester operationTester ConnectionSpecified Condition
Operation 4A46±1 ± Body ground10 V or more
Operation 1A46±1 ± Body groundBelow 1.0 V
NG Go to step 4.
OK

B17438
Wire Harness Side:
Air Pump Connector
A43
DI±246
± DIAGNOSTICSENGINE
440 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:

Using the AIR INJ CHECK operation of the SYSTEM CHECK provided in the hand±held tester func-
tion, conditions for air±fuel ratio and pressure in the secondary air injection system passage can be
checked while the secondary air injection system operating. It helps technicians to troubleshoot the
system when it malfunctioning.

Read freeze frame data using a hand±held tester. Freeze frame data record the engine condition when
malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle
was moving or stationary, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, and
other data, from the time the malfunction occurred.
1 Check voltage between terminal 2 of air pump and body ground.
PREPARATION:
(a) Remove the intake manifold (see page EM±36).
(b) Disconnect the A43 air pump connector.
(c) Connect the hand±held tester to the DLC3.
(d) Turn the ignition switch ON and turn the tester ON.
CHECK:
(a) When the air pump is operated using the hand±held tes-
ter, measure the voltage between terminal A43±2 of the
air injection driver connector and body ground.
(b) Select the following menu items: DIAGNOSIS/EN-
HANCED OBD II/SYSTEM CHECK/ AIR INJ CHECK/
MANUAL OPERATION/OPERATION 1 and 3
HINT:
OPERATION 1: AP:OFF, EASV:CLOSE, ASV1:CLOSE,
ASV2:CLOSE
OPERATION 3: AP:ON, EASV:OPEN, ASV1:OPEN,
ASV2:OPEN
NOTICE:
This test only allows technicians to operate the AI system
for 5 seconds. Furthermore, the test can be performed 4
times a trip. If the test is repeated, intervals of at least 30
seconds are required between tests.
While the AI system operation using the hand±held tester
is prohibited, the tester displays the prohibition (WAIT or
ERROR). If the ERROR (AI STATUS NG) is displayed on the
tester, stop the engine for 10 minutes and then try again..
OK:
Standard:
Tester operationTester ConnectionSpecified Condition
Operation 3A43±2 ± Body ground10 V or more
Operation 1A43±2 ± Body groundBelow 1.0 V
NG Go to step 4.
OK

DI±250
± DIAGNOSTICSENGINE
444 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
RltdDTCP0420Bank 1 catalyst is deterioratedRelated DTCsP0430Bank 2 catalyst is deteriorated
Main sensors/componentsFront and rear heated oxygen sensor
Required sensors/componentsRelated sensors/components
Mass air flow meter, Engine coolant temperature
sensor, Engine speed sensor, Intake air tempera-
ture sensor
Frequency of operationOnce per driving cycle
Duration20 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage11 V±
Intake air temperature±10C (14F)±
Engine coolant temperature75°C (167°F)±
Atmospheric pressure coefficient0.75±
IdleOFF
Engine RPM±3,200 rpm
A/F sensorActivated
Fuel system statusClosed loop
Engine load10 to 70 %
All of the following conditions are metCondition 1, 2 and 3
1. MAF6to 75 g/sec
2. Front catalyst temperature (estimated)620to 830C (1,148 to 1,526F)
3. Rear catalyst temperature (estimated)410 to 830C (770 to 1,526F)
Rear HO2S monitorCompleted
Shift position4th±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Oxygen storage capacity (OSC) of catalystLess than 0.16

+25 %
±12.5 %
More than 3.35 V
Less than 3.0 V
1
A/F Sensor (Sensor 1)
Output Voltage
Injection volume
Output voltage
HO2 Sensor (Sensor 2)
Output VoltageMain Suspected
Trouble Areas
OK
+25 %
±12.5 %
More than 3.35 V
Less than 3.0V
Injection volume
Output voltage
+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
A/F sensor+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG OK
OK
OK
Almost
no reaction
'
Almost
no reaction Almost
no reaction
Almost
no reaction
Case
2
3
4
A/F sensor circuit A/F sensor heater
HO2 sensor
HO2 sensor circuit HO2 sensor heater
(Air±fuel ratio extremely
lean or rich)Injector
Gas leakage from
exhaust system Fuel pressure
± DIAGNOSTICSENGINE
DI±253
447 Author: Date:
2005 SEQUOIA (RM1146U)
Standard:
Tester Display
(Sensor)Injection VolumesStatusVoltages
AFS B1S1
(A/F)+25 %RichLess than 3.0
AFS B1S1
(A/F)±12.5 %LeanMore than 3.35
O2S B1S2
(HO2)+25 %RichMore than 0.55
O2S B1S2
(HO2)±12.5 %LeanLess than 0.4
NOTICE:
The Air±Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2)
sensor has a maximum output delay of approximately 20 seconds.
Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs
of both the A/F and HO2 sensors.
To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD
II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2, and press the YES but-
ton and then the ENTER button followed by the F4 button.

DI±250
± DIAGNOSTICSENGINE
444 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
RltdDTCP0420Bank 1 catalyst is deterioratedRelated DTCsP0430Bank 2 catalyst is deteriorated
Main sensors/componentsFront and rear heated oxygen sensor
Required sensors/componentsRelated sensors/components
Mass air flow meter, Engine coolant temperature
sensor, Engine speed sensor, Intake air tempera-
ture sensor
Frequency of operationOnce per driving cycle
Duration20 sec.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Battery voltage11 V±
Intake air temperature±10C (14F)±
Engine coolant temperature75°C (167°F)±
Atmospheric pressure coefficient0.75±
IdleOFF
Engine RPM±3,200 rpm
A/F sensorActivated
Fuel system statusClosed loop
Engine load10 to 70 %
All of the following conditions are metCondition 1, 2 and 3
1. MAF6to 75 g/sec
2. Front catalyst temperature (estimated)620to 830C (1,148 to 1,526F)
3. Rear catalyst temperature (estimated)410 to 830C (770 to 1,526F)
Rear HO2S monitorCompleted
Shift position4th±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Oxygen storage capacity (OSC) of catalystLess than 0.16

+25 %
±12.5 %
More than 3.35 V
Less than 3.0 V
1
A/F Sensor (Sensor 1)
Output Voltage
Injection volume
Output voltage
HO2 Sensor (Sensor 2)
Output VoltageMain Suspected
Trouble Areas
OK
+25 %
±12.5 %
More than 3.35 V
Less than 3.0V
Injection volume
Output voltage
+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
A/F sensor+25 %
±12.5 %
More than 0.55 V
Less than 0.4V
Injection volume
Output voltage
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG
+25 %
±12.5 %
Injection volume
Output voltage
NG OK
OK
OK
Almost
no reaction
'
Almost
no reaction Almost
no reaction
Almost
no reaction
Case
2
3
4
A/F sensor circuit A/F sensor heater
HO2 sensor
HO2 sensor circuit HO2 sensor heater
(Air±fuel ratio extremely
lean or rich)Injector
Gas leakage from
exhaust system Fuel pressure
± DIAGNOSTICSENGINE
DI±253
447 Author: Date:
2005 SEQUOIA (RM1146U)
Standard:
Tester Display
(Sensor)Injection VolumesStatusVoltages
AFS B1S1
(A/F)+25 %RichLess than 3.0
AFS B1S1
(A/F)±12.5 %LeanMore than 3.35
O2S B1S2
(HO2)+25 %RichMore than 0.55
O2S B1S2
(HO2)±12.5 %LeanLess than 0.4
NOTICE:
The Air±Fuel Ratio (A/F) sensor has an output delay of a few seconds and the Heated Oxygen (HO2)
sensor has a maximum output delay of approximately 20 seconds.
Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs
of both the A/F and HO2 sensors.
To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD
II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2, and press the YES but-
ton and then the ENTER button followed by the F4 button.