| DTC Code | DTC Name |
|---|---|
| P0100 | Mass Air Flow Circuit |
DESCRIPTION
The mass air flow meter sub-assembly is a sensor that measures the intake air volume using the following built-in components:
By-pass duct (allows some of the intake air to flow past a silicon chip sensor)
Silicon chip sensor (uses a heater control bridge circuit and temperature sensor bridge circuit to detect the difference in the temperature of the intake air that passes the sensors positioned before and after the heater).
Control circuit (converts the difference in temperature into a pulse signal and performs correction)
Intake air flows past the temperature sensor (before heater), the heater, and then the temperature sensor (after heater) of the silicon chip sensor in the by-pass duct. As the intake air is warmed up when it is exposed to the heater, the temperature of the intake air as it flows past the temperature sensor (after heater) is higher than when it flows past the temperature sensor (before heater). The difference in temperature of the intake air at each temperature sensor varies depending on the velocity of the intake air that flows past the silicon chip sensor. The temperature sensor bridge circuit detects the difference in temperature and the control circuit converts it into a pulse signal and outputs it to the ECM. When the temperature detected by the temperature sensor (before heater) is higher than that detected by the temperature sensor (after heater), backflow of the intake air is detected.
The ECM calculates the intake air volume based on the pulse signal received from the mass air flow meter sub-assembly.
The heater control bridge circuit has a temperature sensor and power transistor, and maintains the heater temperature at a specific temperature.
| *1 | Mass Air Flow Meter Sub-assembly | - | - |
| *a | Silicon Chip Sensor | *b | By-pass Duct |
| *c | Heater | *d | Heater Thermistor |
| *e | Intake Air | *f | Temperature Sensor (After Heater) |
| *g | Temperature Sensor (Before Heater) | *h | Air Flow |
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
|---|---|---|---|---|---|
| P0100 | Mass Air Flow Circuit | Mass air flow meter sub-assembly signal frequency is less than 0.1 kHz with the engine speed at 400 rpm or more for 3 seconds (1 trip detection logic). |
|
Comes on | DTC stored |
| DTC No. | Data List |
|---|---|
| P0100 | MAF |
Tech Tips
If DTC P0100 is stored, the following symptoms may appear (as the ECM mistakenly determines that there is less air than the actual intake air amount, EGR is decreased according to the target EGR):
Combustion noise worsens
CONFIRMATION DRIVING PATTERN
| DTC No. | DTC Detection Drive Pattern |
|---|---|
| P0100 | 3 seconds or more after engine is started |
WIRING DIAGRAM
| *a | VCVG |
| *b | Mass Air Flow Meter Sub-assembly |
CAUTION / NOTICE / HINT
Note
After replacing the ECM, the new ECM needs registration (Click here ) and initialization Click here.
Tech Tips
Read freeze frame data using the GTS. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.
PROCEDURE
CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY)
| *a | Front view of wire harness connector (to Mass Air Flow Meter Sub-assembly) |
Disconnect the mass air flow meter sub-assembly connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the mass air flow meter sub-assembly connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) Click here |
| OK |
|
REPLACE MASS AIR FLOW METER SUB-ASSEMBLY
Replace the mass air flow meter sub-assembly.
| Result | ||
|---|---|---|
|
| NEXT |
|
CHECK IF DTC OUTPUT RECURS (SEE IF DTC P0100 IS OUTPUT AGAIN)
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and wait for 3 seconds or more.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
REPLACE ECM
Replace the ECM.
| Result | ||
|---|---|---|
|
| NEXT |
|
GO TO STEP 7 Click here |
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)
Disconnect the mass air flow meter sub-assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the mass air flow meter sub-assembly connector.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR Click here |
| OK |
|
REPLACE ECM
Replace the ECM.
| Result | ||
|---|---|---|
|
| NEXT |
|
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Clear the DTCs.
Turn the ignition switch off and wait for at least 30 seconds.
Turn the ignition switch to ON and turn the GTS on.
Start the engine and wait for 3 seconds or more.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Confirm that the DTC is not output again.
| Result | ||
|---|---|---|
|
| NEXT |
|
END |
REPAIR OR REPLACE HARNESS OR CONNECTOR
Repair or replace the harness or connector.
| Result | ||
|---|---|---|
|
| NEXT |
|
GO TO STEP 7 Click here |