Facts about Ford  SCP:

  • Ford’s variation of J-1850 is called Standard Corporate Protocol or SCP
  • J1850 PWM – 41.6k Dual Wire is used for OE Data transfer – Pins 2 & 10 – 5v
    uses a two wire twisted pair bus and is the most common network protocol used on late model Ford passenger vehicles.
    The signal has a 0-5 volt toggle and the SCP+ and SCP- signals are mirrored. (Take a look at the signals below).


  • J1850 VPW – 10.4k Single wire used for Global OBD II – Pin 2 only – 7 volts
  • An open on one wire should not affect bus communications
  • A short to ground will cause a loss of communication with scan tool
  • A short to B+ will likely result in a dead bus


This was taken from a EEC-V on bench with no devices attached.
Yellow is SCP+ : The signal is held high and gets pulled low.
Red is SCP- (signal inverted): The signal is held low and gets pulled high.

 

 

 

SCP+ Circuit traced inside early model eec-v (1996)

 

work in progress....