Mass Air Flow (MAF) sensor, checking: Notes

The Mass Air Flow (MAF) sensor signal is used by the control module to calculate the permissible injection quantity and to regulate Exhaust Gas Recirculation (EGR). The smaller the MAF sensor signal is, the lesser fuel may be injected.

NOTE: Use only gold-plated terminals when servicing terminals in harness connector.

Recommended special tools and equipment

V.A.G 1526 multimeter or V.A.G 1715 multimeter
V.A.G 1594 connector test kit
Wiring diagram

Requirement

Fig 1: Identifying Main Fuse Panel

Courtesy of VOLKSWAGEN UNITED STATES, INC.

The respective fuses of Diesel-Direct fuel injection system must be OK:

Refer to Electrical Wiring Diagrams, Troubleshooting & Component Locations

Battery voltage must be at least 11.5 volts.
All electrical consumers such as, lights and rear window defroster must be switched off.
For vehicles with automatic transmission, selector lever must be in -P-.
Parking brake must be engaged.

If vehicle is equipped with an A/C system, it must be switched off.
Ground (GND) connections between engine and chassis must be OK.
Coolant temperature must be at least 80 ° C. Refer to Diagnostic mode 1: Check measured values