P0102

DTC P0102: Mass Air Flow (MAF) Sensor Circuit Low Input

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Confirmation Procedure

NOTE:

Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.

- Intake air temperature: -14 °C (6.8 °F) or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and run it for 10 sec.
4) Check DTC and pending DTC.

DTC Troubleshooting

1.
Was "Engine System Check" performed?
YES
Go to Step 2.
NO
Go to Engine System Check Engine System Check.

2. MAF Sensor Check.

Connect scan tool to DLC with ignition switch turned OFF.
Start engine and check MAF value displayed on scan tool. (Refer to Scan Tool Testing and Procedures Scan Tool Data
for normal value.)

Is normal value indicated?
YES
Intermittent trouble.
Check for intermittent referring to Intermittent and Poor Connection Inspection.
NO
Go to Step 3.

3. Check MAF sensor power supply voltage.

Disconnect connector from MAF sensor with ignition switch turned OFF.
Turn ON ignition switch, measure voltage between engine ground and "BLK/RED" wire terminal.

Is voltage 10 - 14 V?
YES
Go to Step 4.
NO
"BLK/RED" wire in open circuit.

4. Check MAF sensor ground circuit.

Measure resistance between "ORN" wire terminal and engine ground.

Is resistance below 5 ohms?
YES
Go to Step 6.
NO
Go to Step 5.

5. Check ground circuit.

Disconnect connectors from ECM with ignition switch turned OFF.
Remove ECM from vehicle body and connect connectors to ECM.
Measure resistance between "C46-18" terminal and vehicle body ground.

Is resistance below 5 ohms?
YES
"ORN" wire in open or high resistance circuit.
NO
ECM grounds "C45-26" and/or "C46-9" circuit in open or high resistance.
If wires are OK, substitute a known-good ECM and recheck.

6. Check MAF sensor signal circuit.

Turn ON ignition switch.
Measure voltage between "GRN" wire terminal in MAF sensor and engine ground.

Is voltage 0 V?
YES
Go to Step 7.
NO
"GRN" wire shorted to others circuit.

7. Check MAF sensor signal circuit.

Disconnect connectors from ECM with ignition switch turned OFF.
Measure resistance between "GRN" wire terminal and vehicle body ground.

Is resistance infinity?
YES
Go to Step 8.
NO
"GRN" wire shorted to ground circuit.

8. Check MAF sensor signal circuit.

Measure resistance between "GRN" wire terminal in MAF sensor connector and "C46-27" terminal in ECM connector.

Is resistance below 3 ohms?
YES
Go to Step 9.
NO
"GRN" wire in open or high resistance circuit.

9. Check MAF sensor output signal.

Connect connectors to MAF sensor and ECM with ignition switch turned ON.
Check voltage between "C46-24" and "C46-27" under the following condition.

Voltage between "C46-24" and "C46-27" of ECM
Ignition ON, leaving engine stop: 0.5 - 1.0 V
Idling: 1.3 - 1.8 V

Is each value as specified?
YES
Substitute a known-good ECM and recheck.
NO
Faulty MAF sensor.