2001 TOYOTA SEQUOIA engine

B17411
IGF1 IGF2(+) (+)E8
E6
E1 (±)
DI±228
± DIAGNOSTICSENGINE
422 Author: Date:
2005 SEQUOIA (RM1146U)
3 Disconnect ignition coil with igniter connector, and check voltage between ter-
minals IGF1, IGF2 and E1 of ECM connector.
PREPARATION:
(a) Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between the E8 and E6 ECM connectors.
OK:
Standard:
Tester ConnectionSpecified Condition
IGF1 (E8±24) ± E1 (E6±1)4.5 to 5.5 V
IGF2 (E8±25) ± E1 (E6±1)4.5 to 5.5 V
NG Replace ECM (See page SF±80).
OK
Replace ignition coil with igniter.

A21025
Wire Harness Side:
I1
I2
I3I4
I5I6
I7I8
Ignition Coil with Igniter Connector
B17412
E8
IGT8 IGT2
IGT4
IGT5
IGT6IGT3 IGT7IGT1
ECM Connector
± DIAGNOSTICSENGINE
DI±229
423 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check for open and short in harness and connector in IGT signal circuit between
ECM and ignition coil with igniter.
PREPARATION:
(a) Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition with ig-
niter coil connector.
(b) Disconnect the E8 ECM connector.
CHECK:
Check the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
Ignition coil (I1±2) ± IGT1 (E8±8)Below 1 W
Ignition coil (I2±2) ± IGT2 (E8±15)Below 1 W
Ignition coil (I3±2) ± IGT3 (E8±11)Below 1 W
Ignition coil (I4±2) ± IGT4 (E8±10)Below 1 W
Ignition coil (I5±2) ± IGT5 (E8±13)Below 1 W
Ignition coil (I6±2) ± IGT6 (E8±12)Below 1 W
Ignition coil (I7±2) ± IGT7 (E8±14)Below 1 W
Ignition coil (I8±2) ± IGT8 (E8±9)Below 1 W
Ignition coil (I1±2) or IGT1 (E8±8) ±
Body ground10 kW or higher
Ignition coil (I2±2) or IGT2 (E8±15) ±
Body ground10 kW or higher
Ignition coil (I3±2) or IGT3 (E8±11) ±
Body ground10 kW or higher
Ignition coil (I4±2) or IGT4 (E8±10) ±
Body ground10 kW or higher
Ignition coil (I5±2) or IGT5 (E8±13) ±
Body ground10 kW or higher
Ignition coil (I6±2) or IGT6 (E8±12) ±
Body ground10 kW or higher
Ignition coil (I7±2) or IGT7 (E8±14) ±
Body ground10 kW or higher
Ignition coil (I8±2) or IGT8 (E8±9) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK

B17411E8
IGT8
IGT2IGT4
IGT5 IGT6IGT3
IGT7IGT1E1(+)(±) (+) (+)
(+)
(+)
(+)
(+)
(+)
E6
DI±230
± DIAGNOSTICSENGINE
424 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check voltage between terminals IGT1 ± IGT8 and E1 of ECM connector.
PREPARATION:
Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals the E8 and E6 ECM
connectors when the engine is cranked.
OK:
Standard:
Tester ConnectionSpecified Condition
IGT1 (E8±8) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT2 (E8±15) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT3 (E8±11) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT4 (E8±10) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT5 (E8±13) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT6 (E8±12) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT7 (E8±14) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
IGT8 (E8±9) ± E1 (E6±1)More than 0.1 V or less than 4.5 V
NG Replace ECM (See page SF±80).
OK

B17411E8
IGT8
IGT2IGT4
IGT5 IGT6IGT3
IGT7IGT1E1(+)(±) (+) (+)
(+)
(+)
(+)
(+)
(+)
E6
± DIAGNOSTICSENGINE
DI±231
425 Author: Date:
2005 SEQUOIA (RM1146U)
6 Disconnect ignition coil with igniter connector, and check voltage between ter-
minals IGT1 ± IGT8 and E1 of ECM connector.
PREPARATION:
(a) Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.
(b) Turn the ignition switch to ON.
CHECK:
Measure the voltage between terminals the E6 and E8 ECM
connectors when the engine is cranked.
OK:
Standard:
Tester ConnectionSpecified Condition
IGT1 (E8±8) ± E1 (E6±1)4.5 V or more
IGT2 (E8±15) ± E1 (E6±1)4.5 V or more
IGT3 (E8±11) ± E1 (E6±1)4.5 V or more
IGT4 (E8±10) ± E1 (E6±1)4.5 V or more
IGT5 (E8±13) ± E1 (E6±1)4.5 V or more
IGT6 (E8±12) ± E1 (E6±1)4.5 V or more
IGT7 (E8±14) ± E1 (E6±1)4.5 V or more
IGT8 (E8±9) ± E1 (E6±1)4.5 V or more
NG Replace ECM (See page SF±80).
OK

A21025
Wire Harness Side:
I1
I2
I3I4
I5I6
I7I8Ignition Coil with
Igniter Connector
DI±232
± DIAGNOSTICSENGINE
426 Author: Date:
2005 SEQUOIA (RM1146U)
7 Check ignition coil with igniter power source circuit.
PREPARATION:
(a) Disconnect the I1, I2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.
(b) Turn the ignition switch to ON.
CHECK:
Measure the voltage between the terminal of the wire harness
side connector and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
I1±1 ± Body ground
I2±1 ± Body ground
I3±1 ± Body ground
I4±1 ± Body ground9t 14VI5±1 ± Body ground9 to 14 V
I6±1 ± Body ground
I7±1 ± Body ground
I8±1 ± Body ground
OK Repair ignition coil with igniter.
NG

A21025
Wire Harness Side:
I1
I2
I3I4
I5I6
I7I8Ignition Coil with Igniter
A21378
Wire Harness Side:
I18
Ignition SwitchIG2
± DIAGNOSTICSENGINE
DI±233
427 Author: Date:
2005 SEQUOIA (RM1146U)
8 Check for open and short in harness and connector between ignition switch and
ignition coil with igniter.
PREPARATION:
(a) Disconnect the I1, 2, I3, I4, I5, I6, I7 or I8 ignition coil with
igniter connector.
(b) Disconnect the I18 ignition switch connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
Ignition coil (I1±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I2±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I3±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I4±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I5±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I6±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I7±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I8±1) ± IG2 (I18±6)Below 1 W
Ignition coil (I1±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I2±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I3±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I4±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I5±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I6±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I7±1) or IG2 (I18±6) ±
Body ground10 kW or higher
Ignition coil (I8±1) or IG2 (I18±6) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Replace ignition coil with igniter.

B17432
Air PumpPressure
Sensor
Air
Air Injection
Driver (AID)
Air Switching Valve
(ASV)(EASV)Air Switching Valve No.2
(ASV No.2)(ASV1)VSV for Air Injection
Control
ECMEngine Coolant
Temp. Sensor
Mass Air Flow
Meter
Intake Air Temp.
Sensor To Bank 2To Bank1
Air Switching Valve No.2
(ASV No.2)(ASV2)
DI±234
± DIAGNOSTICSENGINE
428 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0412 Secondary Air Injection System Air Switch-
ing Valve ºAº Circuit
CIRCUIT DESCRIPTION
The secondary air injection system pumps air to the exhaust port to accelerate the activation of the catalyst.
The secondary air injection system consists of the ECM, air pump, Air Switching Valve (ASV) (EASV), Air
Switching Valve No.2 (ASV No.2) (ASV1, 2), pressure sensor and air injection driver (AID). The Air Switching
Valve (ASV)(EASV) is an electromagnetic type and Air Switching Valve No.2 (ASV No.2)(ASV1,2) is a vacu-
um type.
The secondary air injection system pumps pressurized air to the exhaust port by the air pump through the
ASV and ASV No.2. The ASV assists the ASV No.2. The ASV No.2 also controls air supply.
The ECM sends signals to the AID, and then the AID operates the air pump and ASV. The pressure sensor
detects pressure and exhaust pulsation in the system when the system operates and when it does not oper-
ate, and sends the data to the ECM.
DTC No.DTC Detection ConditionTrouble Area
P0412
All of the following conditions are met when engine is idling just
after cold start
(1 trip detection logic):
(a) Air injection system does not operate (Air pump OFF and all
ASVs OFF)
(b) Air injection driver diagnostic signal duty is 40%.
Open in air switching valve drive circuit

Short between air switching valve circuit and +B circuit

Air injection driver

Air switching valve

ECM
P0412
All of the following conditions are met when engine is idling just
after cold start
(1 trip detection logic):
(a) Air injection system operates (Air pump ON and all ASVs
ON)
(b) Air injection driver diagnostic signal duty is 40%.

Short between air switching valve circuit and body ground

Air injection driver

Air switching valve

ECM
DIDMV±01

± DIAGNOSTICSENGINE
DI±235
429 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
The air injection driver (AID) detects an open or short in the circuit according to the voltage of the air pump
terminal (VP) and electromagnetic air switching valve terminal (VV), and sends a signal as diagnostic in-
formation to the ECM.
The AID outputs the air switching valve terminal malfunction signal to the ECM if: 1) VV terminal voltage is
low despite the AID receiving the command signal from the ECM to drive the air switching valve terminal or
2) VV terminal voltage is high despite the AID not receiving the command signal from the ECM.
The ECM stores the DTC based on the diagnostic signal from the AID and illuminates the MIL.
MONITOR STRATEGY
Related DTCsP0412Air switching valve circuit malfunction (Second-
ary air injection system)
Required sensors/componentsAir injection driver, Air switching valve
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Case 1:
Air pumpOperating
Air switching valveOperating
Battery voltage8 V±
Ignition switchON
StarterOFF
Case 2:
Air pumpNot operating
Air switching valveNot operating
Battery voltage8 V±
Ignition switchON
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case 1, 2:
Diagnostic signal duty ratio from air injection driver31 to 48 %
COMPONENT OPERATING RANGE
ParameterStandard Value
Diagnostic signal duty ratio from air injection driver
70 to 90% when secondary air injection system operating
and
0% when secondary air injection system not operating