P0102

2AR-FXE ENGINE CONTROL: SFI SYSTEM: P0102, P0103: Mass or Volume Air Flow Circuit Low Input


DESCRIPTION

The mass air flow meter sub-assembly is a sensor that measures the amount of air flowing through the throttle valve. The ECM uses this information to determine fuel injection duration and to provide an appropriate air fuel ratio.

Inside the mass air flow meter sub-assembly, there is a heated platinum wire which is exposed to the flow of intake air. By applying a specific electrical current to the wire, the ECM heats it to a specific temperature. The flow of incoming air cools both the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to the wire and internal thermistor. The voltage level is proportional to the airflow through the sensor, and the ECM uses it to calculate the intake air volume.

The circuit is constructed so that the platinum hot wire and the temperature sensor create a bridge circuit, and the power transistor is controlled so that the potentials of A and B remain equal to maintain the predetermined temperature.

HINT
When any of these DTCs is stored, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine speed and throttle valve position. Fail-safe mode continues until a pass condition is detected.









HINT
When any of these DTCs are output, check the air flow rate using the Techstream. Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / MAF.





MONITOR DESCRIPTION

If there is a defect or an open or short circuit in the mass air flow meter sub-assembly, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the mass air flow meter sub-assembly circuit and stores a DTC.

Example:

When the sensor output voltage remains less than 0.2 V, or higher than 4.9 V for 3 seconds, the ECM stores a DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0102





P0103





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the power switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the power switch off and wait for at least 30 seconds.

5. Turn the power switch on (IG) and turn the Techstream on [A].

6. Put the engine in inspection mode (maintenance mode) Component Tests and General Diagnostics.

7. Start the engine.

8. Idle the engine for 5 seconds [B].

9. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

10. Read the pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

11. During normal driving, increase the vehicle speed to 80 km/h (50 mph) [D].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

12. Depress the accelerator pedal fully to increase the vehicle speed to between 100 and 120 km/h (62 and 75 mph) (engine speed of 4000 rpm or more) and then maintain the speed for at least 5 seconds [E].

CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.

13. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [F].

14. Read the pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

15. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

16. Input the DTC: P0102 or P0103.

17. Check the DTC judgment result.





HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [F] again.

18. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT
Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1. READ OUTPUT DTC (DTC P0102 OR P0103)

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs.

Result





B -- CHECK HARNESS AND CONNECTOR (SENSOR GROUND)
A -- Continue to next step.

2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF MASS AIR FLOW METER SUB-ASSEMBLY)





(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Turn the power switch on (IG).

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - NO. 1 INTEGRATION RELAY)
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT MASS AIR FLOW METER SUB-ASSEMBLY

(a) Inspect the mass air flow meter sub-assembly, referring to the On-vehicle Inspection for Mass Air Flow Meter On-Vehicle Inspection.

(b) Inspect the mass air flow meter sub-assembly, referring to the Inspection for Mass Air Flow Meter Inspection.

(c) Inspect the function of the mass air flow meter sub-assembly.

(1) Connect the Techstream to the DLC3.

(2) Turn the power switch on (IG).

(3) Turn the Techstream on.

(4) Put the engine in inspection mode (maintenance mode) Component Tests and General Diagnostics.

(5) Start the engine.

(6) Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / MAF.

(7) Check that the MAF value changes when the engine is raced.

OK:

The reading changes.

HINT
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly Programming and Relearning.

NG -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal

OK -- REPLACE ECM Removal

5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





HINT
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly Programming and Relearning.

NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

OK -- REPLACE MASS AIR FLOW METER SUB-ASSEMBLY Removal

6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal

7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - NO. 1 INTEGRATION RELAY)

(a) Disconnect the mass air flow meter sub-assembly connector.

(b) Remove the No. 1 integration relay from the engine room relay block and junction block assembly.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE NO. 1 INTEGRATION RELAY Removal