0411 swap wiring confusion experts needed

[oldred95]

I'm doing an 0411 swap on a 96 C1500 project. Seems simple enough. I obtained the proper spreadsheet from Lextech and the repinning all seemed to go pretty well. Prior to the swap I took my new to me used 0411 PCM I got off ebay and fabbed up a bench test harness so I could read and save the file and mostly just make sure I didn't receive a brick in the mail. That went perfectly smooth. Once I did the swap and tried to communicate with the PCM things got considerably less smooth. I have no communication. I check my powers and they are correct. The spreadsheet said to pin Class 2 serial data to pin 59 which come to find out isn't wrong, just not right for my application as I'm not using a BCM and pin 58 is actually the Class 2 circuit. Still nothing. I test my grounds. They all match up with what the spreadsheet says with the exception of C1 pin 60. The spreadsheet says that is the TPS and ECT low reference. On my bench test harness that was the ground for the PCM. One of many grounds but evidently the main one to allow it to power up and communicate. This is where I don't know what to do because after countless google searches, every 0411 C1 connector end view I've found says pin 60 is a low reference for one sensor or another and not the PCM ground like it is on the bench test diagram. Can someone shed some light on this for me? If I ground pin 60 I believe I will have communication but where do I take the TPS/ECT low reference that currently resides on pin 60? Thanks for any and all help.

[joecar]

See attached circuit diagrams from 2001 F-car.

[oldred95]

Thank you for the schematics. I was able get the powers and grounds sorted. Despite that however I still had no communication with the 0411. This is actually a 1995 C1500 that I transplanted a 96 C1500 harness into and then did an 0411 swap with the EFI Connection 24x conversion with LS coil on plug ignition. It has been a process to say the least. Although a 95 and 96 essentially look the same, the engine harness integration with the cab is drastically different. Fortunately the connectors were mostly the same and it was a matter of reverse engineering and repinning countless circuits. Anyway I figured out the ABS and PCM share a class 2 serial data circuit in the 96 harness. It is pin G at the 10 way connector at the ABS control module to be exact. The 95 did not use this because it was OBD1 and UART instead of Class 2. That said there was still a pin G at the ABS module and it was sending a steady 10.58 volts down the class 2 data line and causing the no communication. I unpinned it and everything is happy. I was even able to maintain full function and communication with the air bag and ABS modules on the 95 via a repinned 96 harness.