2001 TOYOTA SEQUOIA check engine

A19288
A/F Relay
A23659
Wire Harness Side:
HT
A38
Sensor 1A/F Sensor Connector
AF+
Front ViewAF±
+B A39
B17415
E7ECM Connector
HA1A
A1A+
A1A±
A2A+
A2A±HA2A
± DIAGNOSTICSENGINE
DI±175
369 Author: Date:
2005 SEQUOIA (RM1146U)
12 Check A/F relay.
PREPARATION:
Remove the A/F relay from the engine room J/B.
CHECK:
Inspect the A/F relay.
OK:
Standard:
Terminal No.ConditionSpecified Condition
3 ± 5Always10 KW or higher
3 ± 5Apply B+ between
terminals 1 and 2Below 1 W
NG Replace A/F relay.
OK
13 Check for open and short in harness and connector between ECM and A/F sen-
sor.
PREPARATION:
(a) Disconnect the A38 or A39 A/F sensor connector.
(b) Turn the ignition switch to ON.
CHECK:
(a) Measure the voltage between the +B terminal of the A/F
sensor connector and body ground.
OK:
Standard:
Tester ConnectionsSpecified Conditions
+B (2) ± Body ground9 to 14 V
PREPARATION:
(a) Turn the ignition switch to OFF.
(b) Disconnect the E7 ECM connector.
CHECK:
(a) Check the resistance.
OK:
Standard (Check for open):
Tester ConnectionsSpecified Conditions
HT (A38±1) ± HA1A (E7±2)
HT (A39±1) ± HA2A (E7±1)Below 1 W
AF+ (A38±3) ± A1A+ (E7±22)
AF+ (A39±3) ± A2A+ (E7±23)Below 1 W
AF± (A38±4) ± A1A± (E7±30)
AF± (A39±4) ± A2A± (E7±31)Below 1 W

A23512
Reference (Bank 1 Sensor 1 System Drawing):
A/F Sensor A/F Relay
Heater
Sensor
A1A+ HA1A
Duty
Control ECM
From
Battery
A/F Heater
Fuse
A1A±
To EFI Relay
DI±176
± DIAGNOSTICSENGINE
370 Author: Date:
2005 SEQUOIA (RM1146U)
Standard (Check for short):
Tester ConnectionsSpecified Conditions
HT (A38±1) or HA1A (E7±2) ± Body ground
HT (A39±1) or HA2A (E7±1) ± Body ground10 kW or higher
AF+ (A38±3) or A1A+ (E7±22) ± Body ground
AF+ (A39±3) or A2A+ (E7±23) ± Body ground10 kW or higher
AF± (A38±4) or A1A± (E7±30) ± Body ground
AF± (A39±4) or A2A± (E7±31) ± Body ground10 kW or higher
NG Replace or replace harness or connector.
OK
14 Replace air fuel ratio sensor.
NEXT

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

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).

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.

± 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.

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.