97 F150 Check Eng Light MAF/MAP

[jyork78]

1997 F150 4.6 Auto/OD 93,000 miles

I borrowed a Snap-on Scanner from a friend. Vehicle shows 10 codes. 5 for the MAP sensor and 5 on the MAF sensor. Previous codes showed the Cam Position Sensor and Random misfire. I changed the Cam sensor and the code seems to have disappeared.

I tried to reset and clear the other 10 codes, but the Check Engine light stays on and the codes will not erase. I'm not that familiar with Fords as this is the first one I've owned in about 10 years. Does the Check Engine Light go off when the problem is fixed, or does it have to be turned off manually? I'm assuming I can clean the MAF sensor and will probably change the MAP sensor.

I would like to reset the light, drive it and see if the light comes on again. Any help with clearing the codes or finding other web sites with information would be appreciated.

Thanks

[mikecee48]

It's unusual that the scan tool won't clear the codes. Try removing the PCM (Powertrain Control Module) fuse for a few minutes to clear the computer's memory. If this doesn't do it, then chances are the computer is sensing an immediate failure every time the engine is started. Some failures require multiple (usually 3) occurrences before the code is set.

Also, be sure and use an electronic contact cleaner to spray down the MAF wires. Any other cleaner, such as a brake, carburetor, etc. cleaner might leave a residue. You can get the electrical contact cleaner at a computer store that services computers, electrical parts stores, and maybe even at some auto part places. And, don't touch the MAF wires, ever, with anything. They make break easily and that's a $150 part from what I've heard. I removed mine from the housing, but it appeared that I could have sprayed them down while still in the air inlet housing as they were visible anyway.

Having both those sensors show bad, at one time, makes me suspicious though of a wiring problem. Have you checked the connections?

[jyork78]

Thanks for the information.

I tried to start the vehicle after clearing the codes and I also cycled the key to see if they cleared. They never did even before I started it. I'll try what you said and look for a wiring problem.

Thanks again