Car shuts off

On almost all cars except Chrysler products, the mass air flow sensor is the most important one for fuel metering calculations. Problems with that sensor can cause crank/no-starts, stalling, hesitations, and other running problems. The first thing is you have to know the exact fault code number. There are over a dozen codes referring to the mass air flow sensor, and they mean very different things.

GM fuel pumps do typically fail by starting up normally, then they stop running after you have been driving a while. The problem is crankshaft position sensors and camshaft position sensors also commonly fail by becoming heat-sensitive, then they work again after cooling down for about an hour. An important clue is to listen for the hum of the fuel pump for one second when you turn on the ignition switch. If you hear that when you have a crank/no-start, chances are the pump is okay. If one of those sensors has failed, the pump will not resume running during cranking, and you will not have spark.

A better way to say that is, "check for spark" when the crank/no-start occurs. If spark is missing, it is very unlikely the fuel pump is bad too. The largest majority of crank/no-starts are caused by loss of fuel pump, injector pulses, and spark, not just one of them.

The MAF sensor only sees air, not fuel. The better suspect is the cleaner is cooling the sensing element when it evaporates. These sensors work by heating a temperature-dependent resistor in the air stream, then the circuitry measures its resistance change caused by the air flow cooling it. The resistance change is also affected by the temperature of the incoming air, so these sensors have an ambient air temperature sensor built in.

The more common problems are the connector terminals have a light film of corrosion on them, and the scratching action from removing and reinstalling the plug makes a temporary clean contact, and there is a leak in the fresh air tube between that sensor and the throttle body. If any air sneaks into the engine that does not go through the MAF sensor, the engine computer will not know about it, and it will not calculate the correct amount of fuel to go with that air.

P0101 - Mass or Volume Air Flow Circuit Low Input.

This can be caused by a defective sensor, but you also have to consider wiring problems. Wiggle the harness while the engine is running. If that causes it to stall, suspect a bare/cut/grounded wire first. Also, a lot of mass air flow sensors will act up when you tap on them with a screwdriver handle while the engine is running.

The next step would be to view live sensor data on a scanner, on a test-drive. That way you can see what the engine computer is seeing when the problem occurs.

I suspect we have a problem with communication, which is REAL common in this industry. Your question centered around the fault code. Is it possible that code was set days, weeks, or months earlier, a repair was done, then the code was never erased? If so, it was a clue that sent us down the wrong path.

Had I read your question closer, you were asking about the engine stalling, not the fault code. That can be caused by the fuel pump, but more commonly by two sensors. In fact, Chrysler fuel pumps almost always fail by failing to start up. That leaves you stranded in your driveway. GM pumps do just the opposite. They almost always start up, then fail while you're driving, leaving you sitting on the side of the road with the stalled engine. Sorry I didn't see that right away.

Very happy to hear you solved it. Come back to see me again.