NIStune Z32 ECU - Manual (Page 8)

5) Exhaust Over Temp Output – pin 33 * Series 1 and Series 2
Z32 ECU uses this line to drive the FICD (Fast Idle Control Device) – for idle up when the
air conditioner is on.
FICD is driven separately on the R33 Series 1 RB25 via the air conditioner system (not via
ECU) and driven from pin 36 on the R33 Series 2 RB25.
On the Series 2 FICD functionality requires routing a wire from the Z32 FICD output driver
(pin 5 of IC621) directly to pin 36 (RB25 FICD output pin) and a track being cut.
Series 1
The R33 RB25 engine uses pin 33 for the Exhaust Overtemp Lamp on the dash. This line
should be disconnected to avoid the lamp being illuminated in the vehicle. This is
accomplished by removing Resistor R651. It is located on the bottom side, 3cm down from
the centre support and slightly to the right.
Note: It is next to another 2 resistors. R651 is the right most resistor. Remember this one
need more heat so be patient.