2001 TOYOTA SEQUOIA Page 18

± 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

± 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

A21375
Engine Room J/B:
EFI
No. 2 Fuse
A21226
Wire Harness Side:
Mass Air Flow Meter Connector
M1
+B
A21376
Engine Room J/B:
EFI Relay
DI±108
± DIAGNOSTICSENGINE
302 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check for open and short in harness and connector between mass air flow meter
and EFI relay.
PREPARATION:
Remove the EFI No. 2 fuse from the engine room J/B.
CHECK:
Check the resistance in the EFI No. 2 fuse.
OK:
Standard:
Below 1 W
PREPARATION:
(a) Install the EFI No. 2 fuse.
(b) Disconnect the M1 mass air flow meter connector.
(c) Remove the EFI relay from the engine room J/B.
CHECK:
Check the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
+B (M1±1) ± Engine Room J/B (EFI
relay terminal 1)Below 1 W
+B (M1±1) or Engine room J/B (EFI relay
terminal 1) ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Check ECM power source circuit
(See page DI±493).

B17412E2G E8
ECM Connector
A21226
Wire Harness Side:
Mass Air Flow Meter Connector
M1
VGE2G
B17412
E8ECM Connector
E2G
VG
± DIAGNOSTICSENGINE
DI±109
303 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check continuity between terminal E2G of ECM connector and body ground.
CHECK:
Check the resistance between terminal of the E8 ECM connec-
tor and body ground.
OK:
Standard:
Tester ConnectionSpecified Condition
E2G (E8±29) ± Body groundBelow 1 W
NG Replace ECM (See page SF±80).
OK
7 Check for open 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
E2G (M1±2) or E2G (E8±29) ±
Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Replace mass air flow meter.

DI±110
± DIAGNOSTICSENGINE
304 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0101 Mass or Volume Air Flow Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0100, P0102 and P0103 on page DI±102.
DTC No.DTC Detecting ConditionTrouble Area
P0101
After engine is warmed up, conditions (a), (b), (c) and (d) con-
tinue for more than 10 seconds:
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Voltage output of the mass air flow meter is more than 2.2
V.
(c) Engine coolant temperature is more than 70 °C (158 °F).
(d) Engine speed is less than 2,000 rpm.

Mass air flow meter
Conditions (a), (b) and (c) continue for more than 10 seconds
at engine speed: (2 trip detection logic)
(a) Engine speed is more than 300 rpm.
(b) Voltage output of the mass air flow meter is less than 1.0 V.
MONITOR DESCRIPTION
The MAF (Mass Air Flow) meter helps the ECM calculate 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 incoming air cools the wire and an
internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the volt-
age applied to these components in the MAF meter. The voltage level is proportional to the air flow through
the MAF meter. The ECM interprets this voltage as the intake air amount. If there is a defect in the MAF meter
or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM inter-
prets this deviation as a defect in the MAF meter and sets a DTC.
Example:
If the voltage is more than 2.2 V at idle or less than 1.0 V at idle OFF, the ECM interprets this as a defect
in the MAF meter and sets a DTC.
MONITOR STRATEGY
RltdDTCP0101Mass air flow meter rationality (Low voltage)Related DTCsP0101Mass air flow meter rationality (High voltage)
Main sensors/componentsMass air flow meter
Required sensors/componentsRelated sensors/componentsEngine speed sensor, Engine coolant tempera-
ture sensor, Throttle position sensor
Frequency of operationContinuous
Duration10 sec.
MIL operation2 driving cycles
Sequence of operationNone
DI3HM±13

± DIAGNOSTICSENGINE
DI±111
305 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
High voltage:
Engine speed±2,000 rpm
MAF meter voltage±4.9 V
Engine coolant temperature70C (158F)±
Low voltage:
Engine speed300 rpm±
MAF meter voltage0.2 V±
Fuel cutOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Mass air flow meter voltage (High voltage)More than 2.2 V (varies with throttle position sensor voltage)
Mass air flow meter voltage (Low voltage)Less than 1.0 V (varies with throttle position sensor voltage)

DI±112
± DIAGNOSTICSENGINE
306 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 Are there any other codes (besides DTC P0101) being output?
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main switch ON.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS/ENHANCED OBD II/DTC INFO/
CURRENT CODES.
CHECK:
Read the DTC using the hand±held tester.
RESULT:
Display (DTC output)Proceed to
ºP0101º and other DTCsA
Only P0101B
HINT:
If any other codes besides P0101 are output, perform the troubleshooting for those codes first.
B Replace mass air flow meter.
A
Go to relevant DTC chart (See page DI±58).