P010C
2UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0102,P0103,P010C,P010D: Mass Air Flow Circuit Low
P010D - Mass or Volume Air Flow "A" Circuit High 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 provide an 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 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 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: Powertrain / Engine and ECT / Data List / All Data / MAF #1 or MAF #2.
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 and P010C:
P0103 and P010D:
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
- When viewed from the rear of the engine assembly, Bank 1 is on the left side and Bank 2 is on the right side.
- Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. 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 VALUE USING TECHSTREAM (MASS AIR FLOW RATE)
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Connect the Techstream to the DLC3.
(c) Turn the Techstream ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF #1 or MAF #2.
(e) Read the values displayed on the Techstream.
Result
NOTICE:
*: The value must change when the throttle valve is open or closed.
C -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems
B -- INSPECT ECM (SENSOR GROUND)
A -- Continue to next step.
2. INSPECT MASS AIR FLOW METER (POWER SOURCE VOLTAGE)
(a) Disconnect the E13 or E22 MAF meter connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI FUSE)
OK -- Continue to next step.
3. INSPECT ECM (VG VOLTAGE)
(a) Put the engine in inspection mode Inspection Mode Procedure.
(b) Measure the voltage according to the value(s) in the table below.
HINT
The shift lever should be in the P or N position and the A/C switch should be turned OFF.
Standard voltage:
NG -- CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
OK -- REPLACE ECM Removal
4. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Disconnect the E13 or E22 MAF meter connector.
(b) Disconnect the E1 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MASS AIR FLOW METER (for Bank 1 or Bank 2) Removal
5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - EFI FUSE)
(a) Remove the EFI fuse from the engine room No. 2 relay block.
(b) Disconnect the E13 or E22 MAF meter connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- CHECK ECM POWER SOURCE CIRCUIT ECM Power Source Circuit
6. INSPECT ECM (SENSOR GROUND)
(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPLACE ECM Removal
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
(a) Disconnect the E13 or E22 MAF meter connector.
(b) Disconnect the E1 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MASS AIR FLOW METER (for Bank 1 or Bank 2) Removal