DI98 DIGNOSTICS EINE (1GRFE) DIDT801 DTC P0100 Mass or Volume ir Flow Circuit DTC P010 Mass or Volume ir Flow Circuit Low Input DTC P0103 Mass or Volume ir Flow Circuit High Input CIRCUIT DESCRIPTION The Mass ir Flow (MF) meter measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MF meter, there is a heated platinum wire exposed to the flow of intake air. By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools 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 MF meter. The voltage level is proportional to the airflow through the sensor. The ECM interprets this voltage as the intake air amount. The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with the power transistor controlled so that the potential of and B remains equal to maintain the set temperature. Temperature Sensor B+ Power Transistor Platinum Hot Wire B Output Voltage Temperature Sensor Platinum Hot Wire FI699 09074 09707 DTC No. DTC Detection Condition Trouble rea P0100 P010 P0103 Open or short in mass air flow meter circuit for more than 3 sec. Short in mass air flow meter circuit for more than 3 sec. Short in mass air flow meter circuit for more than 3 sec. (+B circuit) Open or short in mass air flow meter circuit Mass air flow meter ECM 364
DIGNOSTICS EINE (1GRFE) DI99 HINT: fter confirming DTC P0100, P010 or P0103, use the handheld tester to confirm the MF ratio from the LL menu (to reach the LL menu: DIGNOSIS / ENHNCED OBD II / DT LIST / LL). Mass ir Flow Value (gm/sec.) pprox. 0.0 Malfunction Mass air flow meter power source circuit open VG circuit open or short 71.0 or more EVG circuit open MONITOR DESCRIPTION If there is a defect in the MF (Mass ir Flow) meter or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM interprets this deviation as a defect in the MF meter and sets a DTC. Example: When the MF meter voltage output is less than 0. V, or more than 4.9 V, and if either the condition continues for more than 3 sec. MONITOR STRTEGY Related DTCs P0100 P010 P0103 Mass air flow meter circuit range check (Fluttering) Mass air flow meter circuit range check (Low voltage) Mass air flow meter circuit range check (High voltage) Required sensors/components Frequency of operation Duration MIL operation Sequence of operation Mass air flow meter Continuous 3 sec. Immediate (When engine speed is at less than 4,000 rpm) driving cycles (When engine speed is at 4,000 rpm or more) None TYPICL ENBLI CONDITIONS The monitor will run whenever these DTCs are not present The typical enabling condition is not available See page DI18 TYPICL MLFUNCTION THRESHOLDS Detection Criteria Threshold P0100: Mass air flow meter voltage Less than 0. V, or more than 4.9 V P010: Mass air flow meter voltage Less than 0. V P0103: Mass air flow meter voltage More than 4.9 V 365
DI100 DIGNOSTICS COMPONENT OPERTI RE EINE (1GRFE) Mass air flow meter voltage Parameter Standard Value 0.4 to. V WIRI DIGRM B B WL J1 J/C WL GRG Engine Room R/B EFI No. 1 Engine Room R/B EFI Relay 3 1 5 7 J6 BR J/C 4 J7 9 J6 R J/C 6 J7 J8 J/C EFI No. 1 1 R Engine Room R/B WB IE1 GRG Mass ir Flow Meter R 1 E RL +B VG 3 J18 J/C WB W EG B 8 E3 30 9 Battery ECM MREL VG EG 3581 366
DIGNOSTICS EINE (1GRFE) DI101 INSPECTION PROCEDURE HINT: Read freeze frame data using the handheld tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the airfuel ratio was lean or rich, as well as other data from the time when a malfunction occurred. 1 Connect handheld tester, and read value of mass air flow rate. (a) Connect the handheld tester to the DLC3. (b) Turn the ignition switch to ON and push the handheld tester main switch ON. (c) Start the engine. (d) When using handheld tester, enter the following menu: DIGNOSIS / ENHNCED OBD II / DT LIST / LL / MF. Read the mass air flow rate on the handheld tester. RESULT: ir Flow Rate (g/s) Proceed to 0.0 71.0 or more B Between 1 and 70.0 (*1) *1: The value must change when the throttle valve is opened or closed. C B Go to step 6. C Check for intermittent problems (See page DI11). 367
DI10 DIGNOSTICS EINE (1GRFE) Check voltage of mass air flow meter power source. Wire Harness Side: Mass ir Flow Meter Connector +B (a) Disconnect the mass air flow meter connector. (b) Turn the ignition switch to ON. Measure voltage between terminal 1 of the mass air flow meter connector and body ground. 16 +B (1) Body ground 9 to 14 V Go to step 5. 3 Check voltage between terminal VG of ECM connector and body ground. VG ECM Connector EG B17411 Start the engine. Measure the voltage between the specified terminal of the ECM connector. HINT: The shift position should be P or N and the /C switch should be turned OFF. Condition VG (30) EG (9) Engine is idling 0.5 to 3.0 V Replace ECM (See page SF66). 368
DIGNOSTICS EINE (1GRFE) DI103 4 Check for open and short in harness and connector between mass air flow meter and ECM. Wire Harness Side: Mass ir Flow Meter Connector EG VG (a) Disconnect the mass air flow meter connector. (b) Disconnect the ECM connector. Check the resistance between the wire harness side connectors. 16 VG (3) VG (30) ECM Connector EG () EG (9) VG (3) or VG (30) Body ground 10 kω or higher EG VG B1741 Repair or replace harness or connector. Replace mass air flow meter. 369
DI104 DIGNOSTICS EINE (1GRFE) 5 Check for open and short in harness and connector between mass air flow meter and EFI relay. Engine Room J/B: EFI No. 1 Fuse 3509 Remove the EFI No. 1 fuse from the engine room J/B. Check for resistance in the EFI No. 1 fuse. Wire Harness Side: Mass ir Flow Meter Connector +B 16 (a) Install the EFI No. 1 fuse. (b) Disconnect the mass air flow meter connector. (c) Remove the EFI relay from the engine room J/B. Check the resistance between the wire harness side connectors. Engine Room R/B: +B (1) Engine Room J/B (EFI relay terminal 1) +B (1) or Engine room J/B (EFI relay terminal 1) Body ground 10 kω or higher EFI Relay Repair or replace harness or connector. 3461 Check ECM power source circuit (See page DI409). 370
DIGNOSTICS EINE (1GRFE) DI105 6 Check continuity between terminal EG of ECM connector and body ground. ECM Connector Check the resistance between terminal of the ECM connector and body ground. EG (9) Body ground EG B1741 Replace ECM (See page SF66). 7 Check for open in harness and connector between mass air flow meter and ECM. Wire Harness Side: Mass ir Flow Meter Connector EG VG ECM Connector 16 (a) Disconnect the mass air flow meter connector. (b) Disconnect the ECM connector. Check the resistance between the wire harness side connectors. VG (3) VG (30) EG () EG (9) VG (3) or VG (30) Body ground 10 kω or higher EG EG () or EG (9) Body ground 10 kω or higher VG B1741 Repair or replace harness or connector. Replace mass air flow meter. 371