DTC P0100 MASS AIR FLOW SENSOR (MAFS)
[YD]
DTC P0100 MASS AIR FLOW SENSOR (MAFS) PFP:22680
A
Component Description EBS004Q0
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the EC
entire intake air flow. It consists of a hot film that is supplied with
electric current from the ECM. The temperature of the hot film is con-
trolled by the ECM a certain amount. The heat generated by the hot
film is reduced as the intake air flows around it. The more air, the C
greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM D
detects the air flow by means of this current change.
SEF987W
E
CONSULT-II Reference Value in Data Monitor Mode EBS004Q1
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION F
● Engine: After warming up Idle 1.0 - 2.5V
● Air conditioner switch: “OFF”
MAS AIR/FL SE G
● Shift lever: Neutral position 2,000 rpm 2.1 - 2.7V
● No-load
ECM Terminals and Reference Value EBS00BR6 H
Specification data are reference values, and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION: I
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI- J
WIRE DATA
NAL ITEM CONDITION
COLOR (DC Voltage and Pulse Signal)
NO.
A8 R
Power supply for ECM [Ignition switch "ON"]
BATTERY VOLTAGE K
A9 R (11 - 14V)
0.5 - 2.5V
L
[Engine is running]
● Warm-up condition
● Idle speed M
PBIB0389E
A10 R Mass air flow sensor
1.5 - 3.5V
[Engine is running]
● Warm-up condition
● Engine speed is 2,000 rpm
PBIB0390E
[Engine is running]
Mass air flow sensor
A24 B ● Warm-up condition Approximately 0V
ground
● Idle speed
A27 W Sensor's power supply [Ignition switch "ON"] Approximately 5V
EC-1451
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
[YD]
TERMI-
WIRE DATA
NAL ITEM CONDITION
COLOR (DC Voltage and Pulse Signal)
NO.
[Ignition switch “ON”]
[Ignition switch “OFF”]
Approximately 0V
● For a few seconds after turning ignition
D24 G switch "OFF"
ECM relay (self-shutoff)
D26 G
[Ignition switch “OFF”]
BATTERY VOLTAGE
● A few seconds passed after turning ignition (11 - 14V)
switch "OFF"
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
On Board Diagnosis Logic EBS004Q3
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0100 ● An excessively high or low voltage from the sensor ● Harness or connectors
is sent to ECM. (The sensor circuit is open or shorted.)
● Mass air flow sensor
DTC Confirmation Procedure EBS004Q4
WITH CONSULT-II
1. Turn ignition switch “ON”, and wait at least 6 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait at least 3 seconds.
4. If DTC is detected, go to EC-1454, "Diagnostic Procedure" .
SEF817Y
EC-1452
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
[YD]
Wiring Diagram EBS004Q5
EC
TBWA0102E
EC-1453
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
[YD]
Diagnostic Procedure EBS004Q6
1. CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sensor harness connector.
3. Turn ignition switch “ON”.
SEF884Y
4. Check voltage between mass air flow sensor terminals 2, 4 and
ground with CONSULT-II or tester.
Terminal Voltage
2 Approximately 5V
4 Battery voltage
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
PBIB0360E
2. DETECT MALFUNCTIONING PART
Check the following.
● Harness for open or short between mass air flow sensor and ECM
● Harness for open or short between mass air flow sensor and ECM relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
3. Check harness continuity between mass air flow sensor terminal
3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
PBIB0385E
4. DETECT MALFUNCTIONING PART
Check harness for open or short between mass air flow sensor and ECM.
>> Repair open circuit or short to ground or short to power in harness or connectors.
EC-1454
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
[YD]
5. CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT A
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 1 and ECM terminal A10. Refer to Wiring
Diagram. EC
Continuity should exist.
3. Also check harness for short to ground and short to power. C
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. D
6. CHECK MASS AIR FLOW SENSOR
Refer to EC-1455, "Component Inspection" . E
OK or NG
OK >> GO TO 7.
NG >> Replace mass air flow sensor. F
7. CHECK INTERMITTENT INCIDENT
G
Refer to EC-1441, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END H
Component Inspection EBS004Q7
MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconnected. I
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal A10 (Mass air flow sensor
signal) and ground. J
Condition Voltage V
Ignition switch "ON" (Engine stopped.) Approx. 1.0 K
Idle (Engine is warmed up to normal
1.0 - 2.5
operating temperature.)
2,000 rpm (Engine is warmed up to nor- L
2.1 - 2.7
mal operating temperature.)
4. If the voltage is out of specification, disconnect MAFS harness PBIB0361E
connector and connect it again. M
Then repeat above check.
Removal and Installation EBS008YD
MASS AIR FLOW SENSOR
Refer to EM-120, "AIR CLEANER AND AIR DUCT" .
EC-1455
