testing specs for mass air flow sensor?
07-21-2016, 11:44 AM
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You don't have a Mass Air Flow sensor; you have a Volume Air Flow (VAF) sensor. Different technology.
But to answer your question: http://web.archive.org/web/201003261...92volumeai.pdf Note that almost the most important spec is that VS changes smoothly as you open the vane.
But to answer your question: http://web.archive.org/web/201003261...92volumeai.pdf Note that almost the most important spec is that VS changes smoothly as you open the vane.
07-21-2016, 11:51 AM
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Just like the link scope103 provided, do a resistance check to see if you have a good VAF. I never gotten a code for a bad VAF unless it had the cable disconnected. I have seen them not move smoothly and bad numbers on the resistance check and still not throw a code. When installed a bad one on a truck it ran terrible. A resistance check and function check in the yard is well worth the time.
07-21-2016, 12:20 PM
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ok just tested it, and the only thing that came up was E1 to FC, resistance should be zero at other than closed position. I would get .2 - .3 Is this enough to be out of spec?
07-21-2016, 12:24 PM
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You don't have a Mass Air Flow sensor; you have a Volume Air Flow (VAF) sensor. Different technology.
But to answer your question: http://web.archive.org/web/201003261...92volumeai.pdf Note that almost the most important spec is that VS changes smoothly as you open the vane.
But to answer your question: http://web.archive.org/web/201003261...92volumeai.pdf Note that almost the most important spec is that VS changes smoothly as you open the vane.
07-21-2016, 12:52 PM
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The VAF is not designed to be repaired, but with those numbers you don't have much to lose. You can carefully slice the caulking on the top of the VAF and remove the cover. If you're going to try that, do a thorough search here: someone has posted pictures of what you will find.
07-21-2016, 01:04 PM
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No. Assuming those are ohms (and not on the 200kΩ scale or something), even a good (hand-held) digital multimeter has about that much resistance in the leads. So you'll never get a resistance measurement closer than about 1Ω. (And even 10Ω would probably be good enough to close the COR, which is what you're trying to do.)
That's bad. Jumping in one direction is bad, jumping up and down means that you probably have bad contact between the wiper and the resistance coil. Which means the ECM really has no way to tell WHERE the vane is, which is the whole point of the VAF.
The VAF is not designed to be repaired, but with those numbers you don't have much to lose. You can carefully slice the caulking on the top of the VAF and remove the cover. If you're going to try that, do a thorough search here: someone has posted pictures of what you will find.
That's bad. Jumping in one direction is bad, jumping up and down means that you probably have bad contact between the wiper and the resistance coil. Which means the ECM really has no way to tell WHERE the vane is, which is the whole point of the VAF.
The VAF is not designed to be repaired, but with those numbers you don't have much to lose. You can carefully slice the caulking on the top of the VAF and remove the cover. If you're going to try that, do a thorough search here: someone has posted pictures of what you will find.
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07-21-2016, 01:27 PM
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If you get it open, get some circuit cleaner from an electronics shop and clean the area where the wiper fingers contact the resistive substrate on the board. That might get you running again.
Whatever you do, do NOT remove the screws from the connector on the side of the body and attempt to remove that part. You'll destroy the circuit board inside. There's a little wire clip to remove the cable; that's how you detach the wires.
It's best to open up the VAF in a clean environment, such as your kitchen table. When you get done with it, you can temporarily seal it up with duct tape to test it, but use RTV when you're ready to make it permanent.
Whatever you do, do NOT remove the screws from the connector on the side of the body and attempt to remove that part. You'll destroy the circuit board inside. There's a little wire clip to remove the cable; that's how you detach the wires.
It's best to open up the VAF in a clean environment, such as your kitchen table. When you get done with it, you can temporarily seal it up with duct tape to test it, but use RTV when you're ready to make it permanent.
07-21-2016, 01:44 PM
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If you get it open, get some circuit cleaner from an electronics shop and clean the area where the wiper fingers contact the resistive substrate on the board. That might get you running again.
Whatever you do, do NOT remove the screws from the connector on the side of the body and attempt to remove that part. You'll destroy the circuit board inside. There's a little wire clip to remove the cable; that's how you detach the wires.
It's best to open up the VAF in a clean environment, such as your kitchen table. When you get done with it, you can temporarily seal it up with duct tape to test it, but use RTV when you're ready to make it permanent.
Whatever you do, do NOT remove the screws from the connector on the side of the body and attempt to remove that part. You'll destroy the circuit board inside. There's a little wire clip to remove the cable; that's how you detach the wires.
It's best to open up the VAF in a clean environment, such as your kitchen table. When you get done with it, you can temporarily seal it up with duct tape to test it, but use RTV when you're ready to make it permanent.
07-21-2016, 05:37 PM
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I would inspect the pins where they come from the connector and solder on to the PC board. If this is a new vehicle to you, a PO could have made the mistake of undoing the screws and cracked those connections. Just gently wiggle them with a small tweezers and make sure they're solidly attached. If not, you can repair them with a small soldering iron if you're good at that sort of thing. Otherwise bring it to your local electronic geek friend.
Beyond that, there's not much to do beyond making sure the wiper and resistive track are clean. If that doesn't restore smoothly varying readings you need a replacement VAFM.
Beyond that, there's not much to do beyond making sure the wiper and resistive track are clean. If that doesn't restore smoothly varying readings you need a replacement VAFM.
07-22-2016, 08:34 AM
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ok guys, i have taken before pics, so havent cleaned anything yet and I am taking before readings. After inspecting more today, I noticed the on the VC prong where the circuit board is soldered to the top of the prong, the solder is broke lose. So I will try and fix that, and see if I get any better results. Also the sensor that hangs down in the chamber of housing is really dirty(dusty looking). I have pics and will upload later.
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