MAF Sensor problem, 1995 Contour GL, 4cyl

Been struggling with a "check engine light" that comes on. When I pull the DTC I get a strong indication that the MAF Sensor may be the problem.

I've gone so far as cleaning the MAF Sensor, but had no success in correcting the problem. Keep getting the OBD1 fault of 159, "MAF out of range". When using an ohm meter to try to determine the continuity and internal circuitry of the sensor, I keep coming up with "0" ohms between sensor connector terminals "C", and "D", and approximately "4 k" ohms between terminals "C" and "E", and "4k" ohms between terminals "D" and "E". Without a circuit diagram for the MAF sensor itself, I can only guess at what appears to be a direct short between the "C" and "D" terminals which would make the MAF sensor bad, and cause the "check engine light" and DTC problem.

So far I have not been successful in locating such a "circuit schematic". The sensor that is on my contour has the following number on it: 93BB 12B579-BA, and this is the common censor that is used on the 95-99 contour and mystique 4 cyl engines.

Does anyone have a schematic for the actual MAF sensor, itself, that will tell me what the circuit is supposed to look like? Are the terminals "C" and "D" supposed to have "0" ohms, ie, directly connected together? Need some practical help here to understand how this MAF sensor is supposed to work, so that I can determine whether this sensor has to be replaced.

You may find that you will be better off just getting another MAF to try out. You could get one from ebay pretty cheap or find a local budy that could let you plug theirs in for a test run. Just remember to disconnect the battery when you make any changes to ensure the car adjusts.
I am having some issues as well and the wiring under the hood it is always a concern.
good luck.
halboy
If you buy one and it doesn't change then you can sell it again.

I wanted to ask how you went about getting the codes on your 95. I have never done it with out a full scan tool but they don't work on this model unless you some special old style that not many place seem to have. I thought there was a way to just use a paper clip or a basic probe.
Can you help me with this one? Sounds like you have a pretty good understanding of the basics at least.
thanks,
Hallboy

I wanted to ask how you went about getting the codes on your 95. I have never done it with out a full scan tool but they don't work on this model unless you some special old style that not many place seem to have. I thought there was a way to just use a paper clip or a basic probe.
Can you help me with this one? Sounds like you have a pretty good understanding of the basics at least.
thanks,
Hallboy

What I use is the paperclip scan. Another term that is sometimes used is the "flash codes" using the dashboard check engine light. And it accomplishes the same thing as the expensive scan tool.

Be sure to write down all of the counted flashes in a group sequence that will represent a number from "1" to "9". Each group sequence is separated by a pause before the next sequence of flashes starts. After the flash sequences stop, turn the key off, and look at your recorded numbers. You will see that you have a pattern of two groups of duplicate three digit numbers. These are the DTC fault codes. Once you have the reported "flash codes", ie, the DTC's, you can go to the Autozone webpage and look them up under the "How to" section. Although this is for another Ford vehicle, the method is exactly the same for all Ford OBD1 engines. http://www.off-road.com/ford/bigbroncos/tech/eec/index.html

You may find that you will be better off just getting another MAF to try out. You could get one from ebay pretty cheap or find a local budy that could let you plug theirs in for a test run. Just remember to disconnect the battery when you make any changes to ensure the car adjusts...


I found a used on on ebay for sale. $39.95 plus $12 S&H. $51+.

From what I've been able to determine so far, I have a AC Delco MAF Sensor assy on the car now. A rebuilt MAF Sensor assy available from Autozone is manufactured quite differently, having a rough unpolished finish of the metal body portion. Mine is all highly polished and smooth aluminum. So I'm a little hesitant in buying and trying the Autozone part. Don't know why there is such a difference, and whether it would affect the performance of the car.

The more I look at my MAF Sensor problem, the more that I'm convinced that the sensor is shorted and defective. Went to the junk yard the other day. They wanted $50 for the MAF Sensor assy. I told them that I didn't need the assy, only the Sensor chip. They would only sell me the assembly. So I'm going to try to find that Sensor chip from another junk yard. Only takes about 5 minutes to remove the two screws to R/R. Would you have any idea where I can find just the Sensor circuit chip?