I have been trying to analyze my problem with my 2001 Saturn SL1 (has 1.9L Auto). Car was running fine when I parked it. Came out and would not turn over (no starter) but the dash lights worked. I checked the fuses and tried it again, then the dash lights were all out but now the engine would turn over but not start (as if fuel pump is not running). I can hear the fuel pump cycle when the ignition is first turned on, so I think that it still works. The engine does fire a few times but will not start (I think it is the fuel pump prime that has supplied just enough gas to fire a few times).

I have done the following:

1. disconnected negative terminal on battery to attempt to reset PCM/ECM (did not know if would do any good, but it didn't).
2. Checked all fuses, all were fine.
3. Disconnected air breather tube and sprayed starter fluid directly into injectors (which did make the car run until the either ran out).
4. The gauges and indicator dash lights do not respond when the ignition is on, including the odometer which is simply black, no display.
5. I attached a Pro-Scan OBD-II to try to read the DTC codes but it would not communicate at all.

I have read that the PCM rarely fails on this vehicle, but I do not know what else to check. If I do have to replace it, can I get away with a used unit? I have to get it reflashed correct? Can this only be done at a dealership?

 

check pos terminal on battery for tightness and corrosion

and check voltage on battery just sitting there and when trying to crank

 

Checked the battery for corrosion (only slight, cleaned it). Tighten connections and checked battery (about 13.5V full charge). The battery is only about 6 months old. The wires seem to be in good shape. Any other suggestions?

 

Recheck your fuse panels (both of them). Sounds like you are missing electrical voltage to part of your control circuitry (IGN fuses - PCM fuse) etc

 

The fuses seem to be entact (unless there is a hairline fracture). I could replace them all to see if that fixes the problem. I will do that today along with any other suggestions people may have. Maybe there is a short in a wire somewhere which will be more difficult to trace down.

I found a used PCM for $20 at a local salvage yard that matches my numbers in case I do need to replace it. If I were to purchase the used PCM, it would need to be reflashed with my VIN and options to work properly, correct?

 

I checked all of the fuses again (all were fine). While I had them out, I hit the terminal blades with a wire brush and pushed them in and out several times to be sure to remove any corosion on the fuse panel terminals. I then wire brushed the battery terminals, battery cable connections and the two ground strap terminals. When I tried it again, it started right up, as if nothing was wrong. I scanned it for DTC codes but none were recorded (no power).

Thanks for the help.

 

Other than mindless chanting which some times is effective, the previous post points out (again) that when an automobile operates in it's intended environment, corriosion of connections is a huge potential problem. Back in the day when the electonics consisted of a light bult or two and a battery, it was a problem. Now that there are sophisticated electronics, it is still a problem. Just the act of unplugging and plugging back up a connector, fuse or even a light bulb, will fix a lot of glitches as is the use of the electrical connection grease that can be purchased at any auto parts store and can be seen on the connectors on the car as supplied by the factory.
So before you say that you have bought a new computor or what ever, and is there any thing else you can do, go through and cycle the connectors and re-grease them to see if the action of cleaning them (by plugging and unplugging) might not have taken care of your problems. That includes battery connections.