I recently acquired a 1995 5-speed that I'm in the process of working the bugs out. I have two questions regarding a couple of codes that it keeps triggering.

If I erase the codes and clear the computer, the car will run OK for as long as I keep it running at the next start up, and the "check engine" light will stay off. But, after I turn it off, it will activate the check engine light upon the next start up. Pulling the codes yields a P0102 and a P0340. Is it normal for the car to wait until the next start up before it kicks on the check engine light? And, my OBDII docs define those codes as:

P0102 - mass or volume air flow circuit low input

P0340 - camshaft position sensor A circuit malfunction (Bank 1 or single sensor)

Are these the same definitions that Ford uses?

 

Everytime you start the car, it runs a quick self diagnosis. If any sensors are not reading reference voltage they trigger a code. You should check the connections and make sure they are secured. If they are, then check for corrosion or dirt in the connections and broken pins or broken wires. The MAF probably needs to be cleaned. As for the camshaft position sensor, do a pinpoint test and see if you are reading source voltage at the connection. Basicly a visual inspection of the parts themselves will usually tell you what is wrong.

 

Thanks for the reply. I basically followed your instructions. Both the MAF and CP sensor turned out to be toast. All fixed now, and the engine throws no bad codes! It looks like it's been awhile since that "check engine" light had a rest. Car runs good now.

 

No problem! Glad to help.