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