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DTC P0102-00: Air Flow Sensor circuit low input
 
 
 
 
CIRCUIT OPERATION
  • Power is supplied by the ECM connector terminal number 76 to the mass airflow sensor connector terminal number 1.
  • The mass airflow sensor connector terminal number 3 is ground through the ECM connector terminal number 98.
  • The sensor signal is inputted to the ECM connector terminal number 78 from the mass airflow sensor connector terminal number 2.
 
 
TECHNICAL DESCRIPTION
  • The mass airflow sensor outputs current that varies in accordance with the intake air volume.
  • The ECM uses the output signal by the mass airflow sensor and the engine speed signal in order to determine the basic injection duration of the fuel injector.
 
 
DESCRIPTIONS OF MONITOR METHODS
There is an abnormality within the mass airflow sensor, it sends a malfunction signal to the ECM.
 
 
MONITOR EXECUTION
Continuous.
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • More than 3 seconds have passed since the power supply mode of the electric motor switch was ON.
  • While engine is running.
  • 12V battery positive voltage is more than 10.0 volts and is less than 16.5 volts.
Judgment Criterion
  • When the sensor malfunction signal (5h) is output for 2 seconds or more as a mass airflow sensor malfunction signal.
 
 
FAIL-SAFE AND BACKUP FUNCTION
Carry out the fuel control by estimating the amount of intake air from throttle opening degree and a normal sensor.
 
 
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Mass airflow sensor failed.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 80: Air flow Sensor
Q: Is the check result normal?
Replace the mass airflow sensor (Refer to ENGINE – Intake and Exhaust, Air Cleaner AIR CLEANER REMOVAL AND INSTALLATION). Then
 
2.STEP 2. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P0102-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
Intermittent malfunction (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).
 
3.STEP 3. Test the OBD-II drive cycle.
After erasing the DTC, carry out test drive with the drive cycle pattern, and recheck the DTC.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Carry out test drive with the drive cycle pattern (Refer to Diagnostic Function, OBD-II Drive Cycle – Pattern 1 OBD- II DRIVE CYCLE).
(3) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC P0102-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
The inspection is complete.