DC - Testing Notes

DESCRIPTION
The Mass Air Flow (MAF) sensor is located between the air cleaner and the throttle body. The MAF sensor uses a hot wire sensing element to measure the amount of air entering the engine. Air passing over the hot wire causes it to cool. The MAF sensor then outputs an analog voltage signal to the Powertrain Control Module (PCM) to determine the intake air mass. The PCM will then calculate the required fuel injector pulse width in order to provide the desired air/fuel ratio.

REMEMBER
To prevent the replacement of good components, be aware that the following non-Electronic Engine Controls (EEC) areas may be at fault:

- Air cleaner element

- Inlet air duct

- Throttle body

This Pinpoint Test is intended to diagnose only the following:

- MAF sensor

- Harness circuits: VPWR, PWR GND, MAF, and MAF RTN

- PCM

NOTE: You should enter this pinpoint test only when you have been directed here from Diagnostic Routines.