help getting bench harness to work

[ltcbm]

I have built a bench harness for a spanish oak controller from a 07 police interceptor. I can not get it to read or scam with any tool. I have the three 12v+ wires on controller wired up (pin 35. 36. 45} and the grounds wired. The two can wire {11, 23} and the feps wired to obd2 connector. the obd2 connector is wired according to print, 16 12v+, 14 can-, 13 feps, 6 can+, 5&4 grounds. i have tried mutiple pcms and can put pcm on car and it reads. I am not really sure about the operation of the feps wire. I have read that some say you have to put 18vdc on it to get it to read. But if this is wired as it is on car not sure why I would have to do this if you dont on car. On the cae I dont read any voltage on feps wire with scanner hooked or unhooked. I have built several bench harness before but for gm controllers. There dont seem to be near the info out there for these compaired to gm. Does anyone have any ideas?

[Montecarlodrag]

FEPS is only for programming. The programming tool sends 18V to the diagnostics port only when the Flash routine is executed, from there it goes directly to the PCM to enable write to the flash chip..
However this signal is not needed to scan and read the tune.

Did you install a terminator resistor to the CAN Bus?
Did you install IGN wires using a toggle switch? You won't be able to read/write Ford PCMs if all 12V IGN are always on, you need a switch to cycle ignition when the software asks you to.

See attached picture, I took it from a car while I was flashing. This shows the 18V in action.

[ltcbm]

I did not put a resistor inline the can wires. Do you remember what size I need

[Montecarlodrag]

120 Ohm
It's not inline, it needs to be between the two CAN wires, in parallel.
In the attached picture you can see how it needs to be wired. The first resistor is present into the ECU, so you just solder the resistor near to the OBD2 port

[busta9876]

I'm working on a 05 Black Oak 5.4 ECM. I was unable to get the ECM to read on my bench harness until I connected OBD2 port pin 13 to the ECM 175B pin 55. (HP Tuners gave error "Controller Unlocker: x11 Service Not Supported") I first monitored voltage on OBD2 port pin 13 , it did not read anything until I clicked "Read" on hp tuners, when it asks for 3 second key off, back on, it went to 17.2 volts. (hp tuner cable is providing this power) As soon as I connected that to the ECM it stopped giving me the error.

This is called FEPS. Not sure what that means. It was on the ECM pinout sheet as "module programming signal" I was able to trace it in the truck schematics to a connector and it was labeled FEPS in the schematic. OBD2 port pinout on schematics did not show a pin 13. I only figured this out by looking on EFI connection and seeing they offer a programming adapter for OBD2 FEPS. Along with this thread, and that info, I got it working.