P0101
DTC P0101 MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFORMANCEComponent Location:
COMPONENT LOCATION
GENERAL DESCRIPTION
The mass air flow sensor (MAF) is located between the air cleaner assembly and throttle body. The MAF uses a hot film type sensing element to measure the mass of intake air entering the engine. This hot film type air flow sensor consists of a hot film sensor, housing and metering ducts. Mass air flow rate is measured by detection of heat transfer from a hot film probe. The change in air flow rate causes change in the amount of heat being transferred from the hot film probe surface to the air. A large amount of intake air represents acceleration or high load condition while a small amount of intake air represent acceleration or idle. The mass of intake air should increase at acceleration and be stable during constant engine speed. The PCM uses this information to determine the injection duration and ignition timing for the desired air/fuel ratio.
DTC DESCRIPTION
If the load value is out of threshold value, the PCM determines that a fault exists and a DTC is stored.
DTC Detecting Condition:
DTC DETECTING CONDITION
Specification:
SPECIFICATION
Schematic Diagram:
SCHEMATIC DIAGRAM
MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector(DLC).
2. Engine "ON" & Warm up the engine to normal operating temperature.
3. Monitor the "MAFS VOLTAGE" parameter on scantool.
Specification : Voltage increases in response to racing (Refer to the table.)
4. Is the MAF sensor parameter displayed within specifications?
YES: Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "W/Harness Inspection" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES: Repair as necessary and go to 'Verification of Vehicle Repair" procedure.
NO: Go to " System Inspection " procedure.
SYSTEM INSPECTION
1. Check Air Cleaner
1. Check the air cleaner for dirt, blockage, or damage.
2. Is the air cleaner damaged or clogged with dirt ?
YES: Repair or Replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "Check Intake System for Air Leak" as below.
2. Check Intake System for Air Leak
1. Check intake tube, breather hose and MAFS for any sources of air leaks.
2. Are there any cracks in intake tube, MAFS or breather hose and are all bands loose and incorrectly installed?
YES: Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Go to "Check Throttle Position Sensor" as below.
3. Check Throttle Position Sensor
1. Disconnect TPS connector and measure resistance between terminals "1" and "3" of the TPS connector.
Specification : Approx. 3.5 - 6.5 KOhm (with throttle valve fully closed) at 20 °C(68 °F)
2. With still TPS connector disconnected, measure resistance between terminals "2" and "3" of the TPS1 connector.
3. With still TPS connector disconnected, measure resistance between terminals "3" and "4" of the TPS2 connector.
4. Operate the throttle valve slowly from the idle position to the full open position and verify that the TPS1's resistance changes smoothly in proportion with the throttle valve opening angle. And the TPS2's resistance changes smoothly in inverse proportion with the throttle valve opening angle.
Specification :
- TPS1's resistance changes smoothly in proportion with the throttle valve opening angle.
- TPS2's resistance changes smoothly in inverse proportion with the throttle valve opening angle.
5. Is the measured resistance of TPS within specifications?
YES: Do "ETS Initialization" and then go to "Component Inspection" procedure.
NO: Substitute with a known-good TPS and check for proper operation. If the problem is corrected, replace TPS and then go to "Verification of Vehicle Repair" procedure.
If TPS needs to be replaced, do "ETS Initialization" after it is replaced.
NOTE:
Procedure of ETS Initialization
1. Erase the trouble codes on PCM
2. Turn the ignition key on less than 1 second and turn it off(Do not start the engine)
3. Turn the ignition key off and keep this condition until the main relay is turned off. (It will takes 10 second)
4. Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM
COMPONENT INSPECTION
1. Visual Inspection
1. Check the MAFS for contamination, deterioration, or damage.
2. Is the MAFS contaminated, deteriorated or damaged?
YES: Repair or replace as necessary and Go to "Verification of Vehicle Repair" procedure.
NO: Go to " Check MAFS" as below.
2. Check MAFS.
1. Engine "ON"
2. Connect Scantool and select the "MAF SENSOR" parameter on the CURRENT DATA.
3. Monitor signal waveform of the "MAF SENSOR" on the Scantool.
Specification : Check that MAF value is increased correspondently with TPS when pressing accelerator pedal.
4. Is the measured signal waveform of MAF sensor displaying correctly ?
YES: Go to "Check PCM" as below.
NO: Substitute with a known - good MAF and check for proper operation. If the problem is corrected, replace MAF and go to "Verification of Vehicle Repair" procedure.
3. Check PCM
1. Ignition "OFF"
2. Connect Scantool and Ignition "ON"
3. Select simulation function on scantool
4. Simulate voltage at terminal 1 of MAF sensor signal connector.
5. Does the signal value of MAP sensor changes according to simulation voltage ?
YES: Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO: Substitute with a known - good PCM and check for proper operation.
If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as "Complete"
5. Are any DTCs present ?
YES: Go to the applicable troubleshooting procedure.
NO: System is performing to specification at this time.