Z32/RB25 - Air Conditioning FICD [PLEASE HELP]

[User_Name]

6) Air Conditioner FICD – pin 36 * Series 2 only
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) as pictured below.

so in my case I'm a bit confused. The only difference between a series 1 and series 2 RB25 are the coil-packs/ignitor and MAF.

When I first purchased my series 2 RB25 engine, it had a huge turbo, injectors, & a Haltech. I got rid of that and went back to stock turbo, injectors, coilpacks, ECU, and wire harness however these stock parts were from a series 1.

I'm stumped. Should I do the #6 Air Conditioning FICD mod since my engine is technically a series 2 engine running series 1 parts? I want my A/C idle to be working properly when A/C is utilized.

Thank You.

[Matt]

The only difference between a series 1 and series 2 RB25 are the coil-packs/ignitor and MAF

Incorrect. FICD lines are routed differently in the ECU loom in Series 2 which is why these changes are in place

It should be noted that the R33 service manual contains incomplete and contradictory information in regards to Series 1/2 differences. We spent many hours going through the manual and much help from Andrew on this forum with this Series 2 documenting and photographing to get the FICD working correctly

You need to follow the Series 2 changes outlined in the manual for Fast idle to run correctly when the air cond is on

[User_Name]

The only difference between a series 1 and series 2 RB25 are the coil-packs/ignitor and MAF

Incorrect. FICD lines are routed differently in the ECU loom in Series 2 which is why these changes are in place

It should be noted that the R33 service manual contains incomplete and contradictory information in regards to Series 1/2 differences. We spent many hours going through the manual and much help from Andrew on this forum with this Series 2 documenting and photographing to get the FICD working correctly

You need to follow the Series 2 changes outlined in the manual for Fast idle to run correctly when the air cond is on

Great! Thank you for your help Matt.

I am running a Series 1 ECU loom on a Series 2 Motor and you did say "FICD lines are routed differently in the ECU loom in Series 2", So since im not using a series 2 ECU loom would it still apply to me to do the FICD mod for series 2?

Should i be doing ALL of the series 2 mods instead of Series 1?

I hope this makes sense.

Thank You! It's much appreciated.

[Matt]

If you are using a Series 1 loom then use the Series 1 changes (no FICD change) since the AFM and coil pack location differences wont matter here

[User_Name]

If you are using a Series 1 loom then use the Series 1 changes (no FICD change) since the AFM and coil pack location differences wont matter here

Thanks for the clarity Matt.
I don't believe I see my RPMs kick up when the AC is activated tho.

[Matt]

You can monitor the FICD solenoid output by puting a meter on the connector plug. It should go 12V when the air cond compressor kicks in

[User_Name]

You can monitor the FICD solenoid output by puting a meter on the connector plug. It should go 12V when the air cond compressor kicks in

12v is not applied to my solenoid. I have followed series 1 RB25 steps as i have a series 1 wire loom running a series 2 motor.

[User_Name]

I'm a little confused, maybe I am just thinking about this WAY too hard, however looking at my RB25 series 1 loom at the connector, there is no wire coming out of pin 36. This is is supposedly the RB25 FICD output. Is the supposed to be a wire coming out of this location?

I already have the 2k ohm resistor on pin 36 & 30.

Looking at the ECU pin location supplied with the z32 RB25 ECU mod pdf, wouldn't it be ping 46 & not 36? Pin 46 is Air Conditioning SW signal whereas pin 36 shows nothing.

This is driving me a little nuts as i want this ECU to function just like the stock RB25 ECU as my FICD is working properly on the stock ECU.

Is there a wire i can probe at the ECU to find the 12v FICD reading when A/C is activated? This would be much easier then having to probe the solenoid as i am using the greddy intake manifold.

Should i just remove the 2k ohm resistor so it doesn't conflict?

Thank you for your help.

[Matt]

I'm a little confused, maybe I am just thinking about this WAY too hard, however looking at my RB25 series 1 loom at the connector, there is no wire coming out of pin 36. This is is supposedly the RB25 FICD output. Is the supposed to be a wire coming out of this location?

If you were running a Series 2 loom, yes it would be a wire coming out of this

It appears you must be running a Series 1 loom

Series 1
Series 1 does not have a wire connected to this pin. This input can be simulated by fitting a 2K resistor between pin 36 and GND (pin 30) – which will give a reading of around 25 degrees fuel temp (other values can also be used eg: 1K = 40 degrees).

I already have the 2k ohm resistor on pin 36 & 30.

This is fine leave it there

Looking at the ECU pin location supplied with the z32 RB25 ECU mod pdf, wouldn't it be ping 46 & not 36? Pin 46 is Air Conditioning SW signal whereas pin 36 shows nothing

That is the air cond input signal to the ECU. This is different than the FICD output signal from the ECU.

Just follow the Series 1 mods since it looks like you have a Series 1 loom

[User_Name]

I'm a little confused, maybe I am just thinking about this WAY too hard, however looking at my RB25 series 1 loom at the connector, there is no wire coming out of pin 36. This is is supposedly the RB25 FICD output. Is the supposed to be a wire coming out of this location?

If you were running a Series 2 loom, yes it would be a wire coming out of this

It appears you must be running a Series 1 loom

Series 1
Series 1 does not have a wire connected to this pin. This input can be simulated by fitting a 2K resistor between pin 36 and GND (pin 30) – which will give a reading of around 25 degrees fuel temp (other values can also be used eg: 1K = 40 degrees).

I already have the 2k ohm resistor on pin 36 & 30.

This is fine leave it there

Looking at the ECU pin location supplied with the z32 RB25 ECU mod pdf, wouldn't it be ping 46 & not 36? Pin 46 is Air Conditioning SW signal whereas pin 36 shows nothing

That is the air cond input signal to the ECU. This is different than the FICD output signal from the ECU.

Just follow the Series 1 mods since it looks like you have a Series 1 loom

I have followed the series 1 mods but my FICD is not working. Since the 2k ohm resistor is already there, cpuld I also do the series 2 mod for FCID or will I burn sonething up?

[Matt]

It appears you have a wiring inconsistency. You need to go over the wiring (as per attached diagrams) and find/fix the problem


S1 FICD relay is triggered by the A/C auto amp which also feeds into the A/C input switch signal (pin 46) of the ECU. Pin 2 of the FICD relay triggers the relay which activates the solenoid. The Pin 3 (thermostate amp) connected to (2-19) A/C auto amp enables the air cond and FICD relay/solenoid. This input feeds into pin 46 to adjust injection accordingly when A/C is on

As for ECU leave as is for S1 wiring

[User_Name]

It appears you have a wiring inconsistency. You need to go over the wiring (as per attached diagrams) and find/fix the problem


S1 FICD relay is triggered by the A/C auto amp which also feeds into the A/C input switch signal (pin 46) of the ECU. Pin 2 of the FICD relay triggers the relay which activates the solenoid. The Pin 3 (thermostate amp) connected to (2-19) A/C auto amp enables the air cond and FICD relay/solenoid. This input feeds into pin 46 to adjust injection accordingly when A/C is on

As for ECU leave as is for S1 wiring

How is it that I have wiring inconsistency when my FICD works flawlessly with the stock ECU connected.

I appreciate your help

Thank you
I suppose I can look over my wiring but as stated. It works with stock ecu

[Matt]

I'm not sure then with this. What is the part number on your original ECU? I will use this to identify if that is S1 or S2 ... or something else?!

Attached is the R33 S2 FICD documentation, you can see this controlled by the ECU via pin 36, which from your photo does not exist and the S1 wiring doesnt have a FICD output from the ECU as per my previous wiring diagrams posted. So now I'm very confused

The S2 documentation was put together by Andrew and verified on his vehicle. I've also wired that up for another R33 customer with S2 after their FICD did not function when the S1 ECU setup was used

There was a S1.5 released which is a mixture of the two. I'm unclear what changes there are there. We will start with the ECU part number which currently works

[User_Name]

I'm not sure then with this. What is the part number on your original ECU? I will use this to identify if that is S1 or S2 ... or something else?!

Attached is the R33 S2 FICD documentation, you can see this controlled by the ECU via pin 36, which from your photo does not exist and the S1 wiring doesnt have a FICD output from the ECU as per my previous wiring diagrams posted. So now I'm very confused

The S2 documentation was put together by Andrew and verified on his vehicle. I've also wired that up for another R33 customer with S2 after their FICD did not function when the S1 ECU setup was used

There was a S1.5 released which is a mixture of the two. I'm unclear what changes there are there. We will start with the ECU part number which currently works

23710 21U01

[Matt]

That ECU part number is Series 1 R33 RB25DET. So it explains why no FICD output from ECU

Does consult report 'Air cond' on the consult view panel when air conditioner is on? Pin 46 is the 'air conditoner switch signal' into the ECU

There is a 'Air conditioner relay (A/C cut signal) on pin 9 however. This is triggered from Pin 46. Pin 9 this however runs the A/C relay and Aux eletric fan. That may not be triggering from this ECU perhaps? Check with meter

FICD solenoid comes from A/C auto amp which is somehow connected to that

This is not something we have ever had to deal with before with using these ECUs on Series 1. wondering if there is a problem with your Z32 ECU output (pin 9) which does the same thing as the R33 ECU