P0103

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

DESCRIPTION

The Mass Air Flow (MAF) meter is a sensor that measures the amount of air flowing through the valve.

The ECM uses this information to determine the fuel injection time and to prove appropriate air-fuel ratio.

Inside the MAF meter, 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 given 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 these components in the MAF meter. 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 provide 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 are set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is calculated by the ECM, according to the engine RPM and throttle valve position. Fail-safe mode continues until a pass condition is detected.









HINT
When any of these DTCs are set, check the air-flow rate by entering the following menus on the Techstream: Powertrain / Engine / Data List / MAF.





MONITOR DESCRIPTION

If there is a defect in the MAF meter or an open or short circuit, the voltage level deviates from the normal operating range. The ECM interprets this deviation as a malfunction in the MAF meter and sets a DTC.

Example:

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

If the malfunction is not repaired successfully, a DTC is set 3 seconds after the engine is next started.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS

P0102:

P0102::

P0103:

P0103::

COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





- Connect the Techstream to the DLC3.

- Turn the engine switch on (IG) and turn the Techstream on.

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

- Turn the engine switch off and wait for at least 30 seconds.

- Turn the engine switch on (IG) and turn the Techstream on [A].

- Start the engine.

- Idle the engine for 5 seconds [B].

- Enter the following menus: Powertrain / Engine / Trouble Codes / Pending [C].

- 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.
- Run the engine at an engine speed of 4000 rpm for 5 seconds [D].

- Enter the following menus: Powertrain / Engine / Trouble Codes / Pending [E].

- 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.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.

- Input the DTC: P0102 or P0103.

- 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 UNKNOWN, perform steps [B] through [C] again.
- If no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.

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

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 be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction Freeze Frame Data.

PROCEDURE

1. READ DTC OUTPUT

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Select the following menu items: Powertrain / Engine / Trouble Codes.

(e) Read the DTC.

Result:





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

2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)

(a) Disconnect the B33 mass air flow (MAF) meter connector.





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

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

Standard voltage:





(d) Reconnect the MAF meter connector.

NG -- INSPECT FUSE (EFI NO. 3)
OK -- Continue to next step.

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

(a) Disconnect the B33 MAF meter connector.

(b) Disconnect the B12 ECM connector.

(c) Measure the resistance between the terminals.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reconnect the MAF meter connector.

(e) Reconnect the ECM connector.

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

4. INSPECT MASS AIR FLOW METER

(a) Perform On-vehicle Inspection Testing and Inspection.

(b) Inspect the function of the mass air flow meter.

(1) Remove the mass air flow meter with the connector connected.

(2) Connect the Techstream to the DLC3.

(3) Turn the engine switch on (IG).

(4) Turn the Techstream on.

(5) Enter the following menus: Powertrain / Engine / Data List / MAF.

(6) Blow air to the mass air flow meter and check that the intake air amount reading changes.

OK:

The reading changes.

NG -- REPLACE MASS AIR FLOW METER Removal

OK -- REPLACE ECM

5. INSPECT FUSE (EFI NO. 3)

(a) Remove the EFI No. 3 fuse from the engine room relay block.





(b) Measure the EFI No. 3 fuse resistance.

Standard resistance:

Below 1 Ohms

(c) Reinstall the EFI No. 3 fuse.

NG -- REPLACE EFI NO. 3 FUSE
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ENGINE ROOM JUNCTION BLOCK)

(a) Disconnect the B33 MAF meter connector.

(b) Remove the engine room junction block from the engine room relay block.

(c) Measure the resistance between the terminals.

Standard resistance (Check for open):





Standard resistance (Check for short):





(d) Reinstall the engine room junction block.

(e) Reconnect the B33 MAF meter connector.

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

7. INSPECT ENGINE ROOM JUNCTION BLOCK (EFI RELAY)

(a) Remove the engine room junction block from the engine room relay block.





(b) Inspect the EFI relay.

(1) Measure the EFI relay resistance.

Standard resistance:





(c) Reinstall the engine room junction block.

NG -- REPLACE ENGINE ROOM JUNCTION BLOCK

OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit

8. CHECK HARNESS AND CONNECTOR (SENSOR GROUND)

(a) Disconnect the B33 MAF meter connector.

(b) Measure the resistance between the terminals.

Standard resistance:





(c) Reconnect the MAF meter connector.

OK -- REPLACE MASS AIR FLOW METER Removal
NG -- Continue to next step.

9. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

(a) Disconnect the B33 MAF meter connector.

(b) Disconnect the B12 ECM connector.

(c) Measure the resistance between the terminals.

Standard resistance (Check for open):





(d) Reconnect the MAF meter connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM