Ignition "OFF" & Engine "OFF".

Check that arrow mark on the MAFS is indicating correct direction.

Check any contamination, corriosion or damage on connector.

Check that air cleaner is clogged or wet.

Check that MAFS cylinder is deformed, blocked by any foreign material or contaminated.

Is the MAFS visually O.K ?

YES

▶ Go to "Check MAFS" as below.

NO

▶ Substitute with a known-good MAFS and check for proper operation.

If the problem is corrected, replace MAFS and then go to "Verification of Vehicle Repair" procedure.

Engine "ON".

Warm up the engine to normal operating temperature.

Check any leakage on intake system(Leakage or damage on intercooler hose).

Check that EGR does not operate around 90sec elasped after sudden accelleration.

If necessary, disconnect EGR vaccum hose.

Monitor "MASS AIR FLOW" parameter on the CURRENT DATA.

Specification : 500mg/st ± 50mg/st

Is current data displayed correctly ?

YES

▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

NO

▶ Substitute with a known-good MAFS and check for proper operation.

If the problem is corrected, replace MAFS and then go to "Verification of Vehicle Repair" procedure.