Mass Airflow Sensor -G70-, CHECKING
Observe all safety precautions: SAFETY PRECAUTIONS
View clean working conditions: CLEAN WORKING CONDITIONS
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 fuse is 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 connections between engine/transmission/chassis OK.
- Coolant Temperature at least 55° 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 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:
-- Condition may be intermittent
-- Check the intake duct for air leaks, loose connections.
-- Check the wiring for an open, high resistance or short to ground.
-- 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.
-- Switch the ignition On.
-- Using a Multimeter, Check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminal 5 to Ground (GND) for voltage.
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 | Mass Airflow Sensor -G70-, CHECKING => Checking wiring |
| If the specified value was obtained: | Check reference signal circuit | Mass Airflow Sensor -G70-, CHECKING => Checking wiring |
Checking wiring
-- Remove the Engine Control Module (ECM) - J623 -. Refer to appropriate service information.
-- Using a Multimeter, Check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector to the Engine Control Module (ECM) - J623 - electrical harness connector T94 for an open circuit.
| Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminals | Engine Control Module (ECM) - J623 - electrical harness connector T94 terminal and Fuse, (Refer to applicable wiring diagram for fuse positions). |
|---|---|
| 4 | 39 |
| 5 | Fuse, (Refer to applicable wiring diagram for fuse positions). |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring connection for an open or short circuit.
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection and replace any open fuses
-- Go to Final procedures
If the specified value was obtained:
-- If no faults were found Replace the Engine Control Module (ECM) - J623 -. Refer to appropriate service information.
-- Go to Final procedures
Checking wiring
-- Remove the Engine Control Module (ECM) -J623-. Refer to appropriate service information.
-- Using a Multimeter, Check the Mass Air Flow (MAF) Sensor -G70- electrical harness connector to the Engine Control Module (ECM) -J623- electrical harness connector T94 for an open circuit.
| Mass Air Flow (MAF) Sensor -G70- electrical harness connector terminals | Engine Control Module (ECM) -J623- electrical harness connector T94 terminals |
|---|---|
| 1 | 18 |
| 2 | 23 |
| 3 | Blank |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring connection for an open circuit, short circuit to Battery positive or Ground
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
-- Go to Final procedures
If the specified value was obtained:
-- Replace the Mass Air Flow (MAF) Sensor -G70-. Refer to appropriate service information.
Final procedures
-- Reinstall the engine cover and Air Filter Housing, if necessary. Refer to the appropriate service information.
-- After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .