Info for anyone swapping to a Z32 computer.

1) Knock Sensor inputs – pin 23/24

RB25 uses twin knock sensors. Z32 uses one. As a result only one knock sensor will be active if Z32 ECU is left stock. RB25 knock sensor wires 23 (cylinder 1-3) and 24 (cylinder 4-6) are fed to single knock sensor input (pin 23) on the Z32 ECU. Benefits are that knock sensing from both knock sensors is used.



2) O2 Sensor inputs – pin 29/55

RB25 uses single O2 sensor. Z32 uses twin. Link the O2 sensor input for RB25 (pin 29) to pin 55 so both O2 sensor inputs (LHS and RHS) receive a signal. This avoids the potential condition of RHS bank being open circuit (& assigned a default value of 0.3 volts by the ECU) meaning a potentially lean condition.



3) Power Steer switch input – pin 19/34

RB25 power steering input goes to pin 19. This pin is used to drive the rad fan relay on Z32, so this signal must be moved to the Z32 power steer input pin (pin 34). This is achieved by linking across to the correct pin and then isolating the original pin by cutting a track on the board.



4) Full throttle switch input – pin 33

Z32 uses a switch to sense wide open throttle. This is not used on the RB25 – it has an ABS input on this pin, so it must be disconnected. This is achieved by removing a resistor on the reverse side of the ECU.



5) FICD output – pin 33

Z32 uses pin 33 to drive the FICD (Fast Idle Control Device – for idle up when aircon is on). This pin goes to the Exhaust Overtemp Lamp on the R33 dash, so it’s best this is disconnected. FICD is driven separately on the R33 via the Aircon system.



6) Fuel Temperature input – pin 36

Z32 uses a fuel temperature sensor. This is not used on the RB25 and the matching pin does not have a wire connected. A Diagnostic Trouble Code (DTC) will be raised be the Z32 ECU if it senses that the voltage on this pin is out of range. This input can be simulated by fitting a 2 kohm resistor between pin 36 and GND – which will give a reading of around 25 degrees fuel temp.



7) Injectors – pins 105, 110, 112, 114

R33’s actually seem to run fine without changing the injector pins around but theoretically they should be swapped as Z32 and R33 firing order is different.

Z32 to R33 injector wiring changes
R33 pin 105 to Z32 pin 110 (Injector)
R33 pin 110 to Z32 pin 105 (Injector)
R33 pin 112 to Z32 pin 114 (Injector)
R33 pin 114 to Z32 pin 112 (Injector)