S197 CaptKaos' 2011 S197 LS Swap Build Thread Profile - S197 Mustangs

[Captkaos]

Sunday August 21st, 2023: With the previous data in had I went about to bypass the FPCM. As I didn't want to commit to this 100%, I just did the normal bypass loop on the wiring. After testing this with the Ford wiring intact (minus the Fuel Pump Control Module) I found that key on turned on the pump and it was on all the time the key was on. So that part was a success.


Moving on I went on to temporarily bypass the fuel pump relay in the battery junction box and connected a wire to the Holley pump trigger and inserted it in the triggered side of the relay wiring. Now with the Key on, the Holley primed the pump for 5 seconds per setup as expected. Key on also added 52lbs of pressure to the rails.



Now it was time to test the whole thing, needless to say, it now cranks and runs off the Holley controlling the pump. Now I just need to hard wire all of this in and get to where I can tweak the tune and drive the car. After I started this and was checking the trans fluid when I went from park to reverse to neutral then drive, the second time around it actually Died going into Nuetral. Not sure why that happened but...

 

[Captkaos]

Thursday August 24th, 2023: Ordered some potting epoxy trying to be fancy with the connector that I Chopped off the ECM (hence why it is trash) and soldered some wires in the connector and then poured in the potting epoxy. I haven't soldered in FOREVER and it was my first time trying the whole Potting experiment. neither were pretty when I was done but it did permanently fix the starting circuit.

 

[Captkaos]

Saturday August 26th, 2023: Moved the car out of the garage again and set out to solve the Electric fan issue. After reading wiring diagrams and probing the harness we finally found the solution to get power to the fans.
The PCM power circuit that is the only one on the car that provides Hot in Run and Start is grounded by the ECM, since mine is in the trash we grounded the circuit and fan is now operational.

Once that was solved it was time to get the Holley to control them, we removed the default Terminator X controls and setup custom ones and finally had them triggered to come on.

Of course with this whole process there has to be some kind of drama. While we were sorting the fans out we wanted them to only be on during run, so we ran it a lot without the fan.. Once we got it working what better way to cool the car down than to drive it.. That drive ended with us in the middle of the road with no gas in the tank. thanks to my Father-in-Law for rescuing us.



Since it was the monthly cruise in we decided to try and make it but showed up too late and the parking lot was empty.



Here is a passenger shot of us running down the road.

 

[Captkaos]

Sept 4th, 2023: As of today I have about 300 miles on the car. Minus the fact that I junked the Factory ECM and haven't found what signal need for CAN on the Holley to make it work so far everything is working as expected. I have just been running it with water so I plan to replace that with coolant. I did have a couple of leaks where I had to tighten the clamps but they seem to be resolved. The steering rack is a reman and it has the twitchy response in turns. I understand this can be corrected by getting a different EPAS Rack.
Daughter is still not confident with the shifter process (and I need to readjust it) but she did say no one she knows would be able to drive the car LOL.
Aug 30 I had an alignment done and it tracks perfectly. Car loves running 80mph down the road.

I am desperately trying to find CAN data for this as I don't want to buy a replacement ECM for just the AC, unless someone knows where I can find one already programmed for Cheap.
If anyone has any direction on the CAN data I could potentially use a Terminator X input to ground an output coming out of the current harness.

We plan to be at LS Fest regardless of the AC working or not (hope it isn't horrible hot).

 

[Dave_W]

Looking at the wiring diagrams at https://iihs.net/fsm/?d=711, the HVAC Module talks to the Powertrain Contol Module over CAN, but it seems everything is hooked to the HVAC module except for the AC Pressure Transducer that's wired to the PCM (pg 4), and the PCM connects to pin 4 of the AC Clutch Relay located in the Battery Junction Box (pg 5), grounding the control side of the relay. If the HVAC Module is just using CAN to tell the PCM to switch the AC Clutch Relay (and the PCM may ignore the command based on the AC Pressure Transducer signal), that should be relatively easy to replicate with your Holley controller. But if the HVAC Module is getting some inputs over CAN from the PCM, that's tougher. I'd suggest giving the Ford Performance tech line a call and see if they can provide some insight.

 

[Captkaos]

If the HVAC Module is just using CAN to tell the PCM to switch the AC Clutch Relay (and the PCM may ignore the command based on the AC Pressure Transducer signal), that should be relatively easy to replicate with your Holley controller. But if the HVAC Module is getting some inputs over CAN from the PCM, that's tougher. I'd suggest giving the Ford Performance tech line a call and see if they can provide some insight.

Pin 12 from the PCM is commanded ground from the CAN off the HVAC to pin 2 of the AC Clutch relay. (pg 5) I can ground pin 12 and power is output on pin 5 (VT-WH) wire is hot when the HVAC is on regardless of AC switch being on/off.
Technically I could put a switch in to connect ground on Pin 12 (WH-BN) and then let the Current Performance AC module control it, but I would have 2 AC switches.
If I had the CAN request I could feed that to the Holley out of 58/58 and have it ground.
Question is would Ford give them information to me?