Electrical 1999 3.8 v6 HELP!! Crank no start odometer reads “———“ radiator fans on, theft light flashing rapidly

[wmburns]

P1233 (fuel pump driver module disabled or off line [fuel pump driver module]) now last night I tested power at the IFS switch

This is not going to be an "easy" one. It going to require some detailed sophisticated tests. If this were my car I would DOUBLE check the quality of the trunk ground to carry a large current (voltage drop), You stated a new fuel pump was installed. I would also rule out a ground fault to the fuel pump RD/BK and BN/PK wires. Sometimes when replacing a fuel pump it's possible to "pinch" the wire loops between the gas tank and the gas tank ring. The fuel pump wires should be isolated from ground and power. This can be tested for.

NOTE!!: You stated that you smell fuel. I can think of something that might explain the symptom. IF the fuel pump signal return line were ground faulted this would make the fuel pump run at 100%. This could explain the fuel smell as well as the DTC code. But you should also hear the fuel pump run all the time.

When the fuel pump was replaced did you have to splice the electrical lines? If so this opens up the possibility the lines were hooked up backwards or are not making good connection.

Honestly I'm not inclined to do the heavy trouble shooting until you have the PATS reprogramming done. Because it still won't start until that is done anyway.

I would also work on the P0112 DTC code. Perhaps look for a connector problem such as bent/pushed pins to the IAT sensor. This model year Mustang should have a separate IAT sensor. The IAT sensor itself could be bad.

Just wondering. Did someone connect a set of jumper cables backwards? Or perhaps when testing for power at the fuel pump connector power was back feed towards the PCM via the fuel gauge or FTP line. This could explain why the PCM failed.

P1233 - Fuel System Disabled or Offline

• Inertia fuel shutoff (IFS) switch needs to be reset
• Open FPDM ground circuit
• Open or shorted FPM circuit
• Damaged IFS switch
• Damaged FPDM
• Damaged PCM
• Also for Escort/Tracer and Mustang:
  • Open FPDM PWR circuit
  • Open B+ circuit to constant control relay module (CCRM) pin 11
  • Open ground to CCRM pin 18 (Mustang)
  • Damaged CCRM

P0112 - Intake Air Temperature (IAT) Circuit Low Input

• Grounded circuit in harness
• Damaged sensor
• Improper harness connection
• Damaged PCM

 

[Stealth TT]

Yes I could smell fuel, I have not the last few times I’ve tried starting tho. I honestly think that it was the fuel that was in the line before because before I put the new PCM in I had correct fuel pressure at the fuel rail when the key would be turned to the on position as well as when cranking (still didn’t hear fuel pump prime strangely). Now after putting in new PCM no pressure at the fuel rail when key is turned to on or when cranking. So I think the fuel I smelt was when I had just put in the new PCM and it was, what was left in the system. Also in terms of why the old PCM failed that seems like what happened, considering no fuses were blown or anything of that matter. I unplugged both connectors for the IAT blew into them to ensure they were clean and plugged them back in and ran the scanner again. Still getting the code for it. I would also like to note that I tested for the battery voltage and noticed it was at 11.88v, is this a problem and should I charge the battery up to a full 12v before trying any tests? No I did not have to cut any wiring or anything when replacing the new fuel pump. So in your opinion you would get the car re-flashed for PATS and see where we are at after that? Should I drop the fuel tank and ensure all my connections are good before getting PATS flashed? Thank you for all your help!

 

[wmburns]

I have tried to give you as much information as possible to help you to make good decisions. IMO knowing HOW the pieces of the puzzle fit together are vital to correct trouble shooting.

I hope you want take this the wrong way but I get the impression that your first method of trouble shooting is to "replace a part". What I'm trying to get you to do is "test a part". It's so much cheaper to not replace good parts. But I understand that not everybody will take the time and effort to learn the how and why of electrical work.

As for your question about PATS. To me it depends upon what your plan is. Do you plan to try a DIY solution? Are you going to call a mobile lock smith? Tow it to the dealer? But having the PATS reprogrammed does take one unknown off of the "the list".

As for your question about dropping the tank to double check the connections. No. I personally wouldn't drop the tank just to "check" the connections. If I suspected a ground faulted fuel pump line I would MEASURE the resistance to ground to see if there is a ground fault.

The lack of fuel pump prime problem could be:

• no power. Note not as likely has power has been confirmed in and out of the trunk IFS. But best to confirm with a load test.
• bad FPDM ground. Think rust from salted roads!
• Bad FPDM itself
• wiring fault between the PCM and FPDM
• bad fuel pump (not as likely in this case IMO). But best to confirm by powering FP directly.
• bad PCM (again not as likely in this case)

Perhaps it might be a good idea to get another FPDM from a salvage yard. A used unit shouldn't be all that expensive. Try car-part.com for some sample prices. But before I did that I would CONFIRM the trunk ground using a test light that LOADS the circuit. I use a store bought test light but there's some information below on a DIY solution. Why is loading a power circuit important? Consider the vital IFS power test. What if there's a weak connection in the line leading to the IFS switch? If tested with a VOM the circuit may test good but when loaded the voltage could fall on it's face. Testing with a load could prevent a VOM false positive test result. Remember you do live in the rust belt and do have the issue of road salt. For more information see the following link.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

Also see the above link for my thoughts on battery voltage.

In my experience helping people on the forums frequently some will get frustrated and bail out when the trouble shooting gets truly difficult. Just look at the large number of threads where the last post is a request for more information and then.....nothing. I'm trying to say in a diplomatic way is if your intention is to "cut your losses" and call a professional it's understandable. What I'm trying to avoid is my writing a "tome" on how to trouble shoot the FPDM only to have it towed to the dealer. Does that make any sense?

If you will do the work I will help you as best I can.

How To Make Your Own Test Lights

View: https://www.youtube.com/watch?v=-L_fw7xn19k

 

[GOvert]

i'm sloowly learning teacher

 

[wmburns]

I have updated a resource with additional information that may help with this problem.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

There's some information on different options for DIY PCM programming that have been added near the end.