How's it going guys, I've been a long time forum creeper and appreciate the vast knowledge of these Ranger and Explorer chassis.

My setup is a 2001 2WD Ranger XLT 3.0L (Flex Fuel) with a 5.0L swap from a 2001 (Production date of 08/00) 2WD Mountaineer. My Ranger runs and the mechanical side of the swap is complete, but I have some issues that I don't quite understand how to get through or where to start.

Issues begin with the fuel pump staying on on if key is on. Pump does not prime for 2 seconds and then turn off. PCM throws a code for it but it will run (P0232 / P0230)
I can shift the transmission into drive and reverse but the truck doesn't want to maintain a good idle and stumbles while in gear. I can give it throttle to keep it running but anymore than barely pressing the throttle will result in big stumbles and the truck will not move quickly like it's in limp mode or something. O/D light was flashing at one point but no longer is and the trans wont really shift. I have a Dakota Digital SGI-100BT controlling the speed signal. Transmission codes are as follows (P1747, P0755, P0743). The last few codes thrown currently are (P0141, P0161, P1409). All 4 O2 sensors are installed in the exhaust and hooked up. I know since its a flex fuel the fuel pressure is like 10lbs less or something like that but before I swap the regulator and adding another variable I want to figure this stuff out. Some of these codes like the trans and O2 sensors seem to lie within the transmission harness from the trans to the PCM. Is it possible there's a short in the harness? I've searched for issues like this but never found anything. Any help is appreciated.

Breakdown of the codes:
P1747 - EPC (Electronic Pressure Control) solenoid circuit shorted
P0755 - Shift Solenoid 2 Electrical fault
P0743 - TCC (Torque Converter Clutch) showing the solenoid valve ON (Low Voltage) when requested OFF (High Voltage)
P0141 - HO2SHTR12 Heater Circuit
P0161 - HO2SHTR22 Heater Circuit Fault
P1409 - EVR circuit Error (EGR controller)
P0232 - Fuel Pump Secondary Circuit High
P0230 - Fuel Pump Primary Circuit Fault High

I have a 2001 EVTM for my Ranger and a 2000 EVTM for the mountaineer. All of the '01 EVTM for the Explorer were sport tracs and from what I've read the Explorer / Mountaineer are the same from 99-01.

 

Just to cover some basics first

The transmission solenoids all share one 12volt wire, then each solenoid has its own ground wire that runs back to the computer
O2 sensor heaters are the same, common 12v wire, each has separate ground wire to computer
Same for fuel pump relay, 12v key on, computer has the ground for coil

With key on the computer looks for 12volts on each of these ground wires, as the voltage just passes thru the "coils" with a small drop, it then can ground each to activate it

I don't have a 4R70W trans plug diagram, but should be similar to the Rangers 4R and 5R plug ins, OHMs will for sure be the same, so you need to test those



O2 heaters have a common fuse and that can also be used for trans solenoids, and EGR solenoid, I don't have diagrams for the V8

Fuel pump can be from the ground wire being shorted to ground, so relay closes with key on(it gets 12v), you have the diagrams so can pull out the relay and test the slots to see if coil has a full time ground


A common issue can happen on installation of a transmission on any vehicle, wires get pinched between engine and bell housing at the top, all these wires would be just above bellhousing..........................
Run your hand around that area and also feel harness wires to see if they may have been pinched and then pull out after that was discovered

 

Thank you for helping out with the wiring and giving me a place to start. Am I measuring resistance values from (say for example on the trans plug) Pins 11 & 12? Pin 10 would be to positive battery and stuff like the shift solenoids would be to battery negative since they're ground? I also don't have any blown fuses which is odd to me with a short.

I thought about the pinched wires on the firewall but I can slide the harness around so its not actively pinched. It may have gotten crushed a little bit when I was jacking up the trans to put the crossmember in and stuff like that so I'll take a closer look.

 

You test OHMs on transmission connector when its unplugged and test from the 12v pin to the ground pin for each solenoid

You can test the truck side of connector for 12v on the pins as they are labelled in your diagrams, key on

You can open up the PCM(computer) and have a look inside for corrosion, it almost reads like a computer issue for that many oddball codes

 

No, with trans connector unplugged you would measure pin 10 to pin 14,(solenoid 2/B) and should see 22 to 48 ohms
Or pin 10 to pin 16(solenoid 1/A) and see 22-48 ohms
Pin 10 is the shared 12v wire inside the transmission for the 4 shift solenoid

Or pin 1 to pin 5 to test TCC solenoid

You are testing the coils inside the solenoids, so there is no positive or negative value just resistance/ohms

You can test truck side of connector for 12v on correct pins, key on
There is no way to test for grounds since computer only grounds these wires when in use

 

Okay, I'll be able to troubleshoot that stuff tonight and I was also thinking of something funky with the PCM because it is a list of odd codes I shouldn't have. Ill take it apart and look at the board too. If its already broken I can't make it any worse lololol. I'll be careful of course

 

Can't hurt these computers by disassembling the case and having a look at the board, you will see

 

Took a look at the truck tonight and ended up getting the problem resolved! I had to extend the 42 pin harness and when I did, 2 LB/OG wires were swapped. The visible clues were the width of the orange stripe being thinner on one wire compared to the other, and that the fuel pump control wire was headed to the transmission lol. Only figured it out once I removed looms and traced the wire to where it should have gone. Now it runs and drives perfect and all codes are gone.

 

Good work