lots of codes... advice on where to start.
 

I have an 01 3.0i.

Driving yesterday had the cruise set at 70. First thing that happened was the car started to jerk a little bit. Then the trans error light came on. Then the car downshifted and ran high rpms. Then the battery light came on and the car was losing power. The car began to backfire and slow to a stop.

I ran the codes. p0102, p0015, p0141, p0444, p0161, p0492, p0491, and p0012.


I charged the battery and tried starting the car and it would not start. If I held the gas pedal to the floor it would start to kick but not start.

I am guessing this is either the battery or alternator due to the number of codes happening at once.

I recently replaced the alternator but I may have gotten a defective unit. I was also suggested to check the fuel pump. I was going to pull the alternator and battery and have them tested, but I am open to other suggestions as well.

Thanks in advance

I think you would need to get it started to diagnose. Clear everything and see if it comes back.

I see a MAF code, that can cause a no-start I believe. You can try unplugging the MAF and then try to start.

I had a fuel pump go out and experienced similar. You can listen for the click of the fuel pump relay in the glove compartment and the fuel pump operating for a few seconds when turning the key to the "on" position. Or check for fuel in the fuel line at the schrader valve.

Batteries and alternators are notorious for causing random codes. Test the battery amd check voltage once you get it started.

To eliminate the battery have it load tested. Most retail auto parts stores will do the test free of charge.

That said, I suspect the issue is low to no fuel pressure. If you turn the key on the pump will run and you can test fuel pressure at the schrader valve which is easily done with a fuel pressure tester also available at auto parts sellers.

Perfect. Thank you both. I am heading to pick up the fuel pressure gauges tomorrow and have battery and alternator tested. After searching the fuel pump issues on here the fuel pump is slowly becoming my top suspect.

Ill follow up tomorrow on what I find.

In case you dont have gauges, for a quick test you can simply turn key to position 2 then press the shrader valve.

No spurt - dead/almost dead pump or no power to pump

Thanks g300d. I did this first and the gas shot out very heavy. I have to assume the pump is good at this point. I did not pick up the pressure tester as I forgot when they were checking the battery and alternator. I will get the pressure gauge and check to make sure it is range.

I had the battery and alternator tested. The battery tested good but the charge was down to 40%. I imagine this was partly for the amount of time I had the doors open and turning the key on and off. Either way the battery was charging for most of the day. The alternator also passed on the machine.

With the battery fully charged and the alternator back in I will see. This seems strangeif it worked since nothing would have changed from the original issue.

This leaves me a little confused where to go from here. I am open to ideas where to head to check.

The car did backfire once when the key was turned today. I was in the front of the car and a large amount of smoke came from under the intake. Not sure where this would have came from or if this was normal, in a backfiring situation kind of way.

You mentioned a MAF code. The MAF may be busted and giving an implausible output causing a no-start. Try unplugging the MAF then starting the car with the MAF unplugged.

Just something to try as I had a MAF go bad in a different car that caused similar and did the above to diagnose.

You can try cleaning the MAF with MAF cleaner to see if that is the cause. I go through MAFs quite often, have never had one fail to the point the engine wouldn't run. Early symptoms are usually the vehicle wont' accelerate normally and engine roars.

Would like to hear more about where the smoke was coming from. If at the base of the runners that could mean you have an intake manifold gasket gone. That would cause a huge vacuum leak. I would do a vacuum test. Since it is not running it would have to be a smoke test which is the best test anyway. There are several youtube videos detailing how to build one, very easy.

Thank you for the replies. Now that you describe engine roaring and slower acceleration I thought in lower rpm it was sluggish when I was running it. It also seemed louder than normal but I thought the new alternator and a bearing was the culprit.

I’ll grab some cleaner and see what happens. lol try plugged or inplugged and see what happens.

FYI, cleaner doesn't always work. Use it liberally and be sure to spray the wires that are kinda hidden. My experience is that even if it works it is time to buy a new one. Cleaning it should at least make a difference but might not fix the problem completely.