Toyota Sequoia (2005). Manual - part 75

–

DIAGNOSTICS

ENGINE

DI–103

297

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

P0100

Mass air flow meter circuit range check 
(Fluttering)

Related DTCs

P0102

Mass air flow meter circuit range check 
(Low voltage)

P0103

Mass air flow meter circuit range check 

(High voltage)

Required sensors/components

Mass air flow meter

Frequency of operation

Continuous

Duration

3 sec.

MIL operation

Immediate (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 operation

None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever these

DTCs are not present

See page 

DI–18

The typical enabling condition is not avail-

able

–

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

P0100:

Mass air flow meter voltage

Less than 0.2 V, or more than 4.9 V

P0102:

Mass air flow meter voltage

Less than 0.2 V

P0103:

Mass air flow meter voltage

More than 4.9 V

F10
Fusible 
Link 
Block

A23554

ECM

VG

E2G

8

E4

30
E8

29

E8

B–W

R–W

2

B

IA4

14

Battery

B

2F

1

2D

1

Engine Room J/B

EFI No. 1

EFI Relay

EFI No. 2

5

3

1

2

2H

2A

2

G–R

J2
J/C

A

B

G–R

IG4

22

G–R

3

IA4

4

B–W

J16
J/C

6

B

W–B

G–R

A

A

J5
J/C

ED

+B

VG

MREL

M1

Mass Air Flow Meter

B–W

G–R

1

4

5

E2G

DI–104

–

DIAGNOSTICS

ENGINE

298

COMPONENT OPERATING RANGE

Parameter

Standard Value

Mass air flow meter voltage

0.4 to 2.2 V

WIRING DIAGRAM

–

DIAGNOSTICS

ENGINE

DI–105

299

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

0.0

A

271.0 or more

B

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

VG

E8

E2G

ECM Connector

DI–106

–

DIAGNOSTICS

ENGINE

300

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 Connection

Specified Condition

+B (M1–1) – Body ground

9 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 Connection

Condition

Specified Condition

VG (E8–30) – 

E2G (E8–29)

Engine is idling

0.5 to 3.0 V

NG

Replace ECM (See page 

SF–80

).

NG