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Tim West
Tim West, ASE Certified Technician
Category: Ford
Satisfied Customers: 4638
Experience:  ASE Certified Service manager of Firestone
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Where is the map sensor located on my 1994 ford F150 with a

Customer Question

Where is the map sensor located on my 1994 ford F150 with a 302 engine?
Submitted: 4 years ago.
Category: Ford
Expert:  Tim West replied 4 years ago.
graphicgraphic

Did you check the wiring to the mass air flow sensor?
Tim West, ASE Certified Technician
Category: Ford
Satisfied Customers: 4638
Experience: ASE Certified Service manager of Firestone
Tim West and 5 other Ford Specialists are ready to help you
Customer: replied 4 years ago.
I looked at the wiring and did not see anything obvious but hopefully this weekend I will take a closer look and read them out. I'm heading out to the parking lot now to see if I can find the MAP, it's the only thing not changed out yet, besides the computer. If I think it is where the arrow is pointing I thought it was the controls for the heating and cooling dampner. But will look again.
Expert:  Tim West replied 4 years ago.
REMOVAL

1. Disconnect negative battery cable.
2. Disconnect vacuum source from manifold absolute pressure sensor.
3. Remove fasteners attaching manifold absolute pressure sensor and bracket assembly below cowl drip rail.

INSTALLATION

To install, reverse removal procedure.

NOTE: When the battery has been disconnected and reconnected, some abnormal drive symptoms may occur while the powertrain control module relearns its adaptive strategy. The vehicle may need to be driven 10 miles or more to relearn the adaptive strategy.graphic
Customer: replied 4 years ago.
There is a vacuum hose to where your picture points , so does that mean the sensor is under the shroud?
Expert:  Tim West replied 4 years ago.
No, I'm pretty sure it's on the friewall.
Customer: replied 4 years ago.
I just looked and it is not anywhere on the firewall. The only 2 vacuum hoses that go to that area are one to the dampner and the other to inside the duct work shroud which i believe is something for the A/C controls, it also has no wires near it. I have traced every vacuum line out and non go to a sensor I have not identified. Thanks Dean
Expert:  Tim West replied 4 years ago.
You are looking passenger side firewall?
Customer: replied 4 years ago.

Yes and the only 2 lines as I said go to the dampner control and to something inside that shroud around the a/c evaporator.

 

Expert:  Tim West replied 4 years ago.
Okay, here is another picture of it.
<h2 class="float-left">
<p id="hd1-1-1"></p>OPERATION</h2><br><br><p>The B/MAP sensor used on some engines is separate from the barometric sensor and is located on the left fender panel in the engine compartment. The barometric sensor signals the PCM of changes in atmospheric pressure and density to regulate calculated air flow into the engine. The MAP sensor monitors and signals the PCM of changes in intake manifold pressure which result from engine load, speed and atmospheric pressure changes.</p><p>
The Manifold Absolute Pressure (MAP) sensor measures the pressure in the intake manifold and sends a variable frequency signal to the PCM. When the ignition is
<i>ON</i>
and the engine
<i>OFF</i>

, the MAP sensor will indicate the barometric pressure in the intake manifold.
</p><h2 class="float-left">
<p id="hd1-1-2"></p>TESTING</h2><br><br><div class="rg-instructions">
<ol start="1" type="1">
<li>
<span>
Connect
<i>MAP/BARO</i>
tester to sensor connector and sensor harness connector. With ignition
<i>ON</i>
and engine
<i>OFF</i>

, use a DVOM to measure voltage across tester terminals. If the tester's 4-6V indicator is ON, the reference voltage input to the sensor is okay.
</span>
</li>
<div class="clear no-float">&nbsp;</div>
<li>
<span>If the DVOM voltage reading is as indicated in the table, the sensor is okay.</span>
</li>
<div class="clear no-float">&nbsp;</div>
</ol>
<br>
</div><h2 class="float-left">
<p id="hd1-1-3"></p>REMOVAL &amp; INSTALLATION</h2><br><br><p>See Figure 1</p><br><br><div class="instruction-image-container">

<div class="inner-image-container">
<img class="repair-figure" src="http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/26/2c/b3/small/0900c15280262cb3.jpg" alt="Click image to see an enlarged view" width="250" height="225"></div>
<div class="tooltip-wrapper">
<a href="../../repairinfo/repairguide/repaiguideOverlay.jsp?src=http://repairguid e.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/26/2c/b3/medium/0900c15280262cb3.&amp;imageType=gif&amp;imageName=Fig.%201:%20Disengage%20the%20MAP%20sensor%20connector,%20then%20unbolt%20the%20sensor%20from%20the%20vehicle" rel="width:950,height:660" id="repair-multibox" class="mb-image2-overlay image-overlay" title="Enlarge"><img class="float-right enlarge-icon" src="../../images/repair_guide/enlarge_icon.gif"><span><img src="../../images/repair_guide/enlarge_tooltip.gif"></span></a>
</div>
<p class="repair-figure-caption">
<span>Fig. Fig. 1: Disengage the MAP sensor connector, then unbolt the sensor from the vehicle</span>
</p>
</div><div class="rg-instructions">
<ol start="1" type="1">
<li>
<span>Disconnect the negative battery cable.</span>
</li>
<div class="clear no-float">&nbsp;</div>
<li>

<span>Disengage the electrical connector and the vacuum line from the sensor.</span>
</li>
<div class="clear no-float">&nbsp;</div>
<li>
<span>Unfasten the sensor mounting bolts and remove the sensor.</span>
</li>
<div class="clear no-float">&nbsp;</div>
</ol>
<br>
</div><b>To install:</b><br><div class="rg-instructions">
<ol start="4" type="1">
<li>
<span>Install the sensor with the mounting bolts and tighten.</span>

</li>
<div class="clear no-float">&nbsp;</div>
<li>
<span>Attach the electrical wiring lead to the sensor.</span>
</li>
<div class="clear no-float">&nbsp;</div>
<li>
<span>Attach the vacuum line to the sensor.</span>
</li>
<div class="clear no-float">&nbsp;</div>
<li>
<span>Connect the negative battery cable.</span>
</li>
<div class="clear no-float">&nbsp;</div>

</ol>
Customer: replied 4 years ago.
Picture did not come through
Expert:  Tim West replied 4 years ago.
graphic

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Tim West
Tim West
Ford Mechanic
4638 Satisfied Customers
ASE Certified Service manager of Firestone