Yeah I figured I would have to get in and start probing wires to see. Today I went out there and started it, and kind of pulled on the wires coming off the MAP, and it would sputter, then idle normally, but still in low power mode. Unplugging the MAP had no effect so im leaning toward the wiring being messed up going there.Of course the EVAP would be on top of the tank after I filled int up.As far as the ECU goes I have a workshop manual coming, should be here by next week. Ill check the lines from there once I get it and update you. I gotta take a break from this car for a minute before I break something out of frustration.

 

At least you didn't get one of them (Aura) that had a defective brake switch. On those cars, the brake lights were on whenever your foot was not on the brake. They turned off when you hit the brake pedal.

Can't believe there were not more accidents

Those cars are known for having electrical system Gremlins. Don't really know much more than that.

Keep in mind that it may be something as simple as corrosion on the sensor pins or the pigtail contacts. Start simple.

 

The factory scanner is very nice even compared to the latest Snap-on model. Didn’t mean to threadjack your Aura thread. It is just that these newer cars are so complicated with many computers talking over high speed networks. My 2020 and newer Fords have four high speed CAN networks and two medium speed networks. I am constantly in the factory repair website learning the new systems that apply to our trucks.

 

My repair manual came in and i think ive found what we were looking for.

 

I fixed a three source v-ref Ford Diesel today. All the sensors on the “b” 5 volt feed were throwing codes and derating the engine. I started with the most likely sensor on that feed. I ran through the tests on the exhaust pressure sensor and it failed the test. Anything in the exhaust stream seem to fail easily especially pressure sensors. I still had four permanent codes that will only clear after an OBD 2 test drive with no problems. My truck passed it’s test drive and came back with no codes stored or pending. Back to work for you!
I see that your car uses two feeds to the accelerator pedal for a nice redundancy. You can still limp home if one feed fails. The manufacturers are getting smarter at our expense. A failed sensor can kill the whole 5 volt circuit. Look at every sensor on the side with the codes. Start with the pressure sensors and see if they are out of range. The car may come back to life with the failed sensor disconnected.

 

Andy,
There are dotted lines external to the BCM and ECM in the schematic. They appear to externally connect pins on either the 5V or GND independent of what is connected to the pins between them. Like external jumpers.
Is this for monitoring purposes? To monitor the voltage at specific pins where the difference in voltage should be zero if all is well? Or are these simply redundant connections as a fail safe for certain sensors?

Also, the individual sensor wiring is marked X1 or X2 at the top/bottom of the wiring that runs from the five volt rail and the gnds respectively. The signals from the BCM are labeled as 5V1 and 5V2.
They can't indicate which reference voltage they are receiving as that is indicated by the diagram itself. Communications designation??

Notwithstanding, said dotted lines seem to bridge 5v1 and 5v2. If this is actually the case, the two voltage sources are not independent and it seems as though it would make it more difficult to troubleshoot, unless you are using the absence of 5 volts on the high side of a sensor that is located between 2 5 volt sources as your criteria for finding open circuits along the 5 volt and ground rails respectively.

If a sensor completely burns up and goes open circuit, that would not be detectable by looking at its 5 volt source pin vs ground. If it becomes a dead short, that's a different story.

A brief explanation of circuit design here would be most appreciated.

 

From that drawing it looks like x1 and x2 are the connector references. The numbers are pin locations in those connectors. Most of the Ford sensors I deal with have three wires. V-ref, signal return and a value. Looking for a voltage drop.

 

so i pulled the fuel line under the hood to siphon the tank to almost empty in case I have to drop the tank, then ran live data. I cleared the codes and the code for the traction contol and whatnot, and the car ran just fine until I hit a crest on my street, then it went back to previous performance. EVAP looks to show 0 so Im leaning toward that EVAP sensor on top of the tank giving me all this grief

 

You mean fuel pressure sensor, yes?

Do not run your vehicle with almost no fuel in the tank. The fuel pump uses the gas around it as a heat sink. Generally you want to keep a minimum of 1/4 tank to keep the entire fuel pump submerged in gasoline. Otherwise, you are letting the pump heat up which will likely shorten its life. I know this is a special case for testing. Just saying in everyday life not to do this if at all possible.

 

Yeah that. And I know i don't ever run my cars low on gas. It's barely under a quarter but I wanted to recreate the environment it had before it stopped running right and also prep for tank drop.