With Speed Density

This display indicates air flow in grams per second (gm/sec). Readings should be the same as for the Mass Air Flow (MAF) sensor position (4-7 gm/sec) if no malfunction exists in the MAF circuit. If trouble code 33 or 34 is set, the reading will remain fixed at the value that the failure has detected.

NOTE: Vehicles equipped with Speed Density Do Not use the Mass Air Flow (MAF) sensor. There will be no output signal. Test as a 1989 vintage vehicle.