2001 TOYOTA SEQUOIA engine

B17411
HT1B
E7HT2B
E8
DI±100
± DIAGNOSTICSENGINE
294 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check voltage between terminals HT1B, HT2B of ECM connectors and body
ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals of the ECM connectors
and body ground.
HINT:

Connect terminal HT1B to the bank 1 sensor 2.

Connect terminal HT2B to the bank 2 sensor 2.
OK:
Standard:
Tester ConnectionSpecified Condition
HT1B (E8±1) ± Body ground9 to 14 V
HT2B (E7±5) ± Body ground9 to 14 V
OK Replace ECM (See page SF±80).
NG

A23543
+B
OXR2
OXL2E1 HTR2
HTL2
H2
H4
Wire Harness Side:
Bank 1 Sensor 2, Bank 2 Sensor 2
B17416HT1BECM Connector E7OX1B E8
HT2B
OX2B
H24254
Engine Room R/B:
EFI Relay
± DIAGNOSTICSENGINE
DI±101
295 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check for open and short in harness and connector between ECM and heated
oxygen sensor, heated oxygen sensor ± EFI relay.
PREPARATION:
(a) Turn the ignition switch to OFF.
(b) Disconnect the H2 or H4 oxygen sensor connector.
(c) Disconnect the E7and E8 ECM connector.
CHECK:
Check the resistance.
OK:
Standard (Check for open):
Tester ConnectionsSpecified Conditions
HTL2 (H2±1) ± HT1B (E8±1)Below 1 W
HTR2 (H4±1) ± HT2B (E7±5)Below 1 W
Standard (Check for short):
Tester ConnectionsSpecified Conditions
HTL2 (H2±1) or HT1B (E8±1) ±
Body ground10 kW or higher
HTR2 (H4±1) or HT2B (E7±5) ±
Body ground10 kW or higher
PREPARATION:
(a) Turn the ignition switch to OFF.
(b) Disconnect the H2 or H4 oxygen sensor connector.
(c) Remove EFI relay from engine room R/B.
CHECK:
Check the resistance.
OK:
Standard (Check for open):
Tester ConnectionsSpecified Conditions
+B (A21±2) ±EFI relay (3)
+B (A22±2) ± EFI relay (3)Below 1 W
Standard (Check for short):
Tester ConnectionsSpecified Conditions
+B (H2±2) or EFI relay (3) ± Body ground
+B (H2±2) or EFI relay (3) ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Check for intermittent problems
(See page DI±11).

FI6929A09074A09707
Power Transistor
Output
Voltage
AB B+
Temperature Sensor
Platinum Hot Wire
Temperature Sensor
Platinum Hot Wire DI±102
± DIAGNOSTICSENGINE
296 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0100 Mass or Volume Air Flow Circuit
DTC P0102 Mass or Volume Air Flow Circuit Low Input
DTC P0103 Mass or Volume Air Flow Circuit High Input
CIRCUIT DESCRIPTION
The Mass Air Flow (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses
this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MAF meter,
there is a heated platinum wire exposed to the flow of intake air.
By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incom-
ing air cools the wire and an internal thermistor, affecting their resistance. To maintain a constant current
value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is pro-
portional to the airflow through the sensor. The ECM interprets this voltage as the intake air amount.
The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No.DTC Detection ConditionTrouble Area
P0100Open or short in mass air flow meter circuit for more than 3
sec.
P0102Open or short in mass air flow meter circuit for more than 3
sec.
Open or short in mass air flow meter circuit

Mass air flow meter
P0103
Open in mass air flow meter circuit for more than 3 sec. (EVG
circuit)
Short in mass air flow meter circuit for more than 3 sec. (+B
circuit)
Mass air flow meter

ECM
DICEN±02

± DIAGNOSTICSENGINE
DI±103
297 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:
After confirming DTC P0100, P0102 or P0103, use the hand±held tester or the OBD II scan tool to confirm
the MAF ratio from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL).
Mass Air Flow Value (gm/sec.)Malfunction
Approx. 0.0
Mass air flow meter power source circuit open

VG circuit open or short
271.0 or more
EVG circuit open
MONITOR DESCRIPTION
If there is a defect in the MAF (Mass Air Flow) meter or an open or short circuit, the voltage level will deviate
outside the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets
a DTC.
Example:
When the MAF meter voltage output is less than 0.2 V, or more than 4.9 V, and if either the condition contin-
ues for more than 3 sec.
MONITOR STRATEGY
P0100Mass air flow meter circuit range check
(Fluttering)
Related DTCsP0102Mass air flow meter circuit range check
(Low voltage)
P0103Mass air flow meter circuit range check
(High voltage)
Required sensors/componentsMass air flow meter
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (When engine speed is at less than 4,000 rpm)
2 driving cycles (When engine speed is at 4,000 rpm or more)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these
DTCs are not presentSee page DI±18
The typical enabling condition is not avail-
able±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0100:
Mass air flow meter voltageLess than 0.2 V, or more than 4.9 V
P0102:
Mass air flow meter voltageLess than 0.2 V
P0103:
Mass air flow meter voltageMore than 4.9 V

F10
Fusible
Link
Block
A23554
ECM
VG
E2G 8
E4
30
E8
29
E8 B±W R±W
2
B IA414
BatteryB 2F1 2D1 Engine Room J/B
EFI No. 1 EFI Relay
EFI No. 2
5
3
1
2 2H2A2G±R J2
J/C
A
B G±R
IG422
G±R
3 IA44B±W
J16
J/C
6B
W±B G±RA
A
J5
J/C
ED
+B
VG
MREL
M1
Mass Air Flow Meter
B±W
G±R
1
4
5 E2G DI±104
± DIAGNOSTICSENGINE
298 Author: Date:
2005 SEQUOIA (RM1146U)
COMPONENT OPERATING RANGE
ParameterStandard Value
Mass air flow meter voltage0.4 to 2.2 V
WIRING DIAGRAM

± DIAGNOSTICSENGINE
DI±105
299 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 Connect hand±held tester, and read value of mass air flow rate.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to ON and push the hand±held tester main switch ON.
(c) Start the engine.
(d) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / MAF.
CHECK:
Read the mass air flow rate on the hand±held tester.
RESULT:
Air Flow Rate (gm/s)Proceed to
0.0A
271.0 or moreB
Between 1 and 270.0 (*1)C
*1: The value must change when the throttle valve is opened or closed.
B Go to step 6.
C Check for intermittent problems
(See page DI±11).
A

A21226
Wire Harness Side:
+B
Mass Air Flow Meter Connector
M1
B17411
VGE8E2G
ECM Connector
DI±106
± DIAGNOSTICSENGINE
300 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check voltage of mass air flow meter power source.
PREPARATION:
(a) Disconnect the M1 mass air flow meter connector.
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminal 1 of the mass air flow meter
connector and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
+B (M1±1) ± Body ground9 to 14 V
NG Go to step 5.
OK
3 Check voltage between terminal VG of ECM connector and body ground.
PREPARATION:
Start the engine.
CHECK:
Measure the voltage between the specified terminal of the E8
ECM connector.
HINT:
The shift position should be P or N and the A/C switch should
be turned OFF.
OK:
Standard:
Tester ConnectionConditionSpecified Condition
VG (E8±30) ±
E2G (E8±29)Engine is idling0.5 to 3.0 V
NG Replace ECM (See page SF±80).
NG

A21226
Wire Harness Side:
Mass Air Flow Meter Connector
M1
E2GVG
B17412
E8ECM Connector
E2G
VG
± DIAGNOSTICSENGINE
DI±107
301 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check for open and short in harness and connector between mass air flow meter
and ECM.
PREPARATION:
(a) Disconnect the M1 mass air flow meter connector.
(b) Disconnect the E8 ECM connector.
CHECK:
Check the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
VG (M1±3) ± VG (E8±30)Below 1 W
E2G (M1±2) ± E2G (E8±29)Below 1 W
VG (M1±3) or VG (E8±30) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Replace mass air flow meter.