No aftermarket manual (Haynes/Chilton) includes the full ZEXEL pinout. Your best resources:
If you are working on a classic Nissan diesel engine—specifically the legendary (found in the Nissan Patrol GU Y61, Skyline R32/R33 Diesel, or Laurel) or the TD42 with electronic injection—you have likely encountered a mysterious silver box mounted on the firewall or behind the kick panel. This is the ZEXEL ECU . nissan zexel ecu pinout
The Nissan Zexel ECU pinout has numerous applications: Skyline R32/R33 Diesel