P0101
DTC P0101: Mass Air Flow (MAF) Circuit Performance Problem
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
WARNING:
- When performing a road test, select a place where there is no traffic or possibility of a traffic accident and very careful during testing to avoid occurrence of an accident.
- Road test should be carried out with 2 persons, a driver and tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.
- Intake air temperature: -14 °C (6.8 °F) or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature. (ECT approx. 90 - 95 °C, 194 - 203 °F)
4) Increase vehicle speed till engine speed is reached 2000 - 4500 r/min and keep it for 30 sec or more.
5) Stop vehicle and check DTC and pending DTC.
DTC Troubleshooting
1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.
2. Visual inspection.
Check MAF sensor and air intake system for:
Objects which block measuring duct and resistor of MAF sensor.
Other air flow which does not pass the MAF sensor.
Are there in good condition?
YES
Go to Step 3.
NO
Repair or replace.
3. MAF sensor performance check.
With ignition switch turned OFF, install scan tool.
Start engine and warm up to normal operation temp.
Check MAF value using scan tool, under the following conditions.
MAF value specification
Idling: 1.5 - 4.0 g/sec.
Racing at 2500 r/min: 5.0 - 10.0 g/sec.
Is each value as specified?
YES
Go to Step 11.
NO
Go to Step 4.
4. MAF sensor output voltage check.
Check voltage between "C46-24" and "C46-27" under the following conditions.
Voltage between "C46-24" and "C46-27" of ECM
Ignition switch ON, leaving engine OFF: 0.5 - 1.0 V
Idling: 1.3 - 1.8 V
Is each value as specified?
YES
Poor "C46-24" or / and "C46-27" terminal connection.
If OK, substitute a known-good ECM and recheck.
NO
Go to Step 5.
5. Check MAF sensor power supply voltage.
Disconnect connector from MAF sensor (1) with ignition switch turned OFF.
Turn ON ignition switch, measure voltage between engine ground and "BLK/RED" wire terminal (2).
Is voltage 10 - 14 V?
YES
Go to Step 6.
NO
"BLK/RED" wire in open circuit.
6. Check MAF sensor ground circuit.
Measure resistance between "ORN" wire terminal and engine ground.
Is resistance below 5 ohms?
YES
Go to Step 8.
NO
Go to Step 7.
7. Check ground circuit.
Disconnect connectors from ECM with ignition switch turned OFF.
Remove ECM from vehicle body and connect connectors to ECM.
Measure resistance between "C46-27" terminal and vehicle body ground.
Is resistance below 5 ohms?
YES
"ORN" wire in open or high resistance circuit.
NO
ECM grounds "C45-26" and/or "C46-9" circuit in open or high resistance. If wires are OK, substitute a known-good ECM and recheck.
8. Check MAF sensor signal circuit.
Turn ON ignition switch.
Measure voltage between "GRN" wire terminal in MAF sensor and engine ground.
Is voltage 0 V?
YES
Go to Step 9.
NO
"GRN" wire shorted to others circuit.
9. Check MAF sensor signal circuit.
Disconnect connectors from ECM with ignition switch turned OFF.
Measure resistance between "GRN" wire terminal and vehicle body ground.
Is resistance infinity?
YES
Go to Step 10.
NO
"GRN" wire shorted to ground circuit.
10. Check MAF sensor signal circuit.
Measure resistance between "GRN" wire terminal in MAF sensor connector and "C46-27" terminal in ECM connector.
Is resistance below 3 ohms?
YES
Faulty MAF sensor.
NO
"GRN" wire in open or high resistance circuit.
11. MAP sensor performance check.
Check voltage between "C45-7" and "C46-27".
Voltage between "C45-7" and "C46-27" of ECM
Ignition switch ON, leaving engine OFF: 3.3 - 4.3 V at barometric pressure 100 kPa (760 mmHg)
Idling: 0.7 - 1.6 V at barometric pressure 100 kPa (760 mmHg)
Is each value satisfied?
YES
Substitute a known-good ECM and recheck.
NO
MAP performance problem.
Check MAP sensor referring to Testing and Inspection Manifold Absolute Pressure (MAP) Sensor Inspection.