P0101
Volume Airflow Sensor Circuit:
Connectors:
DTC P0101: Volume Airflow Circuit Range/Performance Problem
CIRCUIT OPERATION
- The volume airflow sensor power is supplied from the MFI relay (terminal No. 4), and the ground is provided on the ECM (terminal No. 34)
- 5-volt power is applied to the volume airflow sensor output terminal (terminal No. 3) from the ECM (terminal No. 61)
- 6.0 - 9.0 volts power is applied to the PCM (terminal No. 19) from the volume airflow sensor (terminal No. 7).
- The PCM (terminal No. 19) controls the airflow sensor reset signal by turning the power transistor within the PCM to "ON" and "OFF" position.
TECHNICAL DESCRIPTION
- While the engine is running, the volume airflow sensor outputs a pulse signal which corresponds to the volume of airflow.
- The ECM
- When the throttle position sensor output voltage is low, the ECM
DESCRIPTIONS OF MONITOR METHODS
Compare load value with volume airflow sensor output frequency.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable
Sensor (The sensor below is determined to be normal)
- Throttle position sensor .
DTC SET CONDITIONS
Logic Flow Chart:
Check Conditions
- Throttle position sensor output voltage is 2 volts or lower.
- Engine speed is lower than 2,000 r/min.
Judgement Criteria
- Volume airflow sensor output frequency has continued to be 800 Hz or higher for 2 seconds.
DTC SET CONDITIONS
Logic Flow Chart:
Check Conditions
- Throttle position sensor output voltage is 1.5 volts or higher.
- Engine speed is higher than 2,000 r/min.
Judgement Criteria
- Volume airflow sensor output frequency has continued to be 60 Hz or lower for 2 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are: )
- Volume airflow sensor failed.
- Open or shorted volume airflow sensor circuit harness damage, or connector damage.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tool:
- MB991502: Scan Tool (MUT-II)
STEP 1. Using scan tool MB991502 , check data list item 12: Volume Airflow Sensor.
CAUTION: To prevent damage to scan tool MB991502 , always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.
1. Connect scan tool MB991502 to the data link connector.
2. Start the engine and run at idle.
3. Set scan tool MB991502 to the data reading mode for item 12, Volume Airflow Sensor.
4. Warm up the engine to normal operating temperature: 80° C to 95° C (176° F to 203° F).
- The standard value during idling should be 10 Hz or more.
- When the engine is revved, the frequency should increase according to the increase in engine speed.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
YES: It can be assumed that this malfunction is intermittent. Refer to INTRODUCTION, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions.
NO: Go to Step 2.
STEP 2. Measure the reset signal voltage at volume airflow sensor connector B-14 by backprobing.
1. Do not disconnect the connector B-14.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No. 7 and ground by backprobing.
- Voltage should be between 6.0 and 9.0 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 6.0 and 9.0 volts?
YES: Go to Step 5.
NO: Go to Step 3.
STEP 3. Check connector B-14 at volume airflow sensor and connector C-111 at ECM
Q: Is the connector in good condition?
YES: Go to Step 4.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 4. Check for short circuit to ground between volume airflow sensor connector B-14 (terminal No. 7) and ECM connector C-111 (terminal No. 19)
Q: Is the harness wire in good condition?
YES: Replace the volume airflow sensor. Then go to Step 9.
NO: Repair it. Then go to Step 9.
STEP 5. Measure the reset signal voltage at volume airflow sensor connector B-14 by backprobing.
1. Do not disconnect the connector B-14.
2. Start the engine and run at idle.
3. Measure the voltage between terminal No. 7 and ground by backprobing.
- When the engine idling, voltage should be 1.0 volt or less.
- When the engine speed is 3,000 r/min, voltage should be between 6.0 and 9.0 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 6.0 and 9.0 volts ?
YES: Go to Step 8.
NO: Go to Step 6.
STEP 6. Check connector B-14 at volume airflow sensor and connector C-111 at ECM
Q: Is the connector in good condition?
YES: Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 9.
STEP 7. Check for open circuit and harness damage between volume airflow sensor connector B-14 (terminal No. 7) and ECM connector C-111 (terminal No. 19)
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 9.
NO: Repair it. Then go to Step 9.
STEP 8. Replace the volume airflow sensor.
1. Replace the volume airflow sensor.
2. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
3. Check the diagnostic trouble code (DTC).
Q: Is DTC P0101 set?
YES: Replace the ECM or PCM. Then go to Step 9.
NO: The inspection is complete.
STEP 9. Test the OBD-II drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0101 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.