Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Mass Air Flow Sensor, Checking: Notes
Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) Sensor - G70-.
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- The Mass Air Flow (MAF) Sensor - G70- fuse OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Coolant Temperature at least 80° C.
- Ignition switched off.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK
Start diagnosis
-- Connect the scan tool.
-- Start engine and let it run at idle.
-- Using the scan tool, Check the air flow quantity of the Mass Air Flow (MAF) Sensor -G70- at idle:
| Diagnostic text | Specified value | |||
|---|---|---|---|---|
| Air flow quantity at Mass Air Flow (MAF) sensor | ||||
|
2.00 to 5.00 g/sec | |||
-- Switch the ignition off.
If the specified value was obtained:
If DTC Memory has a DTC concerning Mass Air Flow (MAF) Sensor - G70 - Fault may be intermittent.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
-- Go to Final procedures
If the specified value was Not obtained:
-- Disconnect the Mass Air Flow (MAF) Sensor - G70 - electrical harness connector.
-- Turn the ignition switch ON.
-- Using a Multimeter, connect the red Multimeter lead to terminal 3 of the Mass Air Flow (MAF) Sensor - G70 - module connector and the black lead to ground.
Specified value: Battery voltage.
-- Switch the ignition off.
If the specified value was Not obtained:
-- Check for an open or short to ground in circuit between terminal 3 and fuse SC 1 in Fuse Panel C.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- Repair the circuit and replace any open fuses.
-- Go to Final procedures
If the specified value was obtained:
-- Connect the black Multimeter lead to terminal 2 of the Mass Air Flow (MAF) Sensor - G70 - harness connector and the red lead to Battery voltage.
-- Turn the ignition switch ON.
Specified value: Battery voltage.
-- Switch the ignition off.
Continue test according to the following table:
| Value | Cause | Test |
|---|---|---|
| If the specified value was not obtained: | Open or shorted circuit | CHECKING WIRING |
| If the specified value was obtained: | Check reference signal circuit | CHECKING WIRING |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.