Testing - Ford Ranger Maintaince And Repair Manual

The sensor utilizes a hot wire sensing element to measure the amount of air entering the engine. The sensor
does this by sending a signal, generated by the sensor when the incoming air cools the hot wire down, to the
PCM. The signal is used by the PCM to calculate the injector pulse width, which controls the air/fuel ratio in
the engine. The sensor and plastic housing are integral and must be replaced if found to be defective.
The Mass Air Flow (MAF) sensor is mounted to the air cleaner housing
The sensing element (hot wire) is a1 thin platinum wire wound on a ceramic bobbin and coated with glass.
This hot wire is maintained at 392°F (200°C) above the ambient temperature as measured by a constant "cold
wire''.

TESTING

1. With the engine running at idle, use a DVOM to verify there is at least 10.5 volts between terminals
Aand Bof the MAF sensor connector. This indicates the power input to the sensor is correct. Then,
measure the voltage between MAF sensor connector terminals Cand D. If the reading is
approximately 0.34−1.96 volts, the sensor is functioning properly.
OPERATION
HOW TO USE THIS BOOK
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