kevinkpk

96 Lumina, 3.1. I don't know what sequence happens when I erase a code. Driving, it will intermittently just die. Crank/start/die. If I erase the code, it will be fine till the next time it just dies, that could be 2 miles, 2 weeks ect. This is like turning the key off, then back on with the SES light, PO101 is the only code. I need to know what exactly happens when I erase the code, is there a reset or ?

tech2

what are you doing to erase the code?

kevinkpk

Using the actron (cheap) scan tool

tech2

to my knowledge, a scan tool should clear the dtc and reset all of the emission monitors.
with the code set, the vehicle may be using fix data for ignoring data due to the fault.
maf is a important input for fuel metering...if its skewed it will stall and not idle.

kevinkpk

Thanks for the response, my problem is why do I have to erase the code to get it to stay running? I've been all over the maf sensor, including replacing it. I'm trying to pin point this issue, and relating the dieing issue with that.

tech2

you probably have a wiring issue with the maf circuit.
if it works like most maf circuits do this:
unplug the maf connector; this should set a circuit high dtc...the maf pid in the scan tool should read 5volts
key on you should have
5v reference voltage on the pink wire
5v on the yellow signal wire
0v on the black grd wire
if you jumper the signal wire to the grd wire the maf pid should read 0v and a circuit low dtc should set.
this confirms the wiring...replace the sensor...if the dtc still sets, replace the pcm.

kevinkpk

Got it. I felt wiring, but the three wires all go to three different places. I checked the HZ on the yellow wire, with my fluke 87, cannot look at the sine wave.The range was between 2400-2200 hz at idle. This is mirrored from around 6 years ago with the pcm issue, I had to replace it then. The other thing with unplugging the maf is sometimes will die, other times it "runs", but not like it should. I only have a cheap actron scan tool, but can piggy back the meter off the connector.

tech2

the 3 wire all go back to the ecm

kevinkpk

That's what I would have thought. Haynes electrical schematic shows pink wire to 15 amp fuses key on under the hood. Black is to a common ground, yellow to the ecm. I verified they pink was battery voltage with key on.

kevinkpk

I've come to the "theory" that something is killing the ignition, the code P0101 is popping up do to no air flow through the maf since the engine has died. What I still don't understand is erasing the code to get it to crank/start, and stay running. I replaced the ignition switch less than two years ago, still at a "almost" complete loss.