RB25DET ecu wiring

[michal_m]

Hello guys.

We are in a process of swaping the RB25DET engine into the BMW E30 chassis. We are working now on wiring harness. We use this ECU diagram:



Could you tell me which ECU pins should get 12V to start the engine and run properly? I assume we need deliver 12V to pins: #49, #58, #59 and #109. What about #43 and #45 pins? Please correct me if I am wrong. Should we deliver to #43 pin which is Start Switch 12V voltage while cranking?

I also have 3 pictures which I want to show you.

1. What is this thing in the red circle? Where does the harness from the white plug go (the yellow circle)?



2. Where does this plug go?



3. Where does this plug go?



Thank you.

Michael.

[l0nestar]

The last two plugs (Pic 2 & 3) look like main chassis plugs - not for the engine harness.
I'm not sure about the 2nd plug (there are a few similar ones in the engine harness).
The first plug .. is that a resistor box? What chassis did this harness come out of?

[d356bud]

The 1st red circled one is for the windshield wipers. l0nestar is correct about the last plug. What are the wire colors of the second plug?

[michal_m]

Are not the thing in the red circle and the plug in the yellow circle (1st picture) connected to the wiper system?

I have next questions related to the ECU pinout.

1. What is in the #36 pin? It is a gray wire and goes to the plug next to the AAC valve. The 2nd wire in that plug is yellow and this wire is cut.

2. The pinout I use tells that the #52 pin was the 1 degree POS signal to the Crank Angle Sensor, but in my ECU plug there is no such wire there. Is it okay?

3. The #43 pin is a Key Switch (Start signal). Should I deliver to this pin 12V while cranking or it is just switched power?

4. The #53 pin is a vehicle speed sensor. The engine is being swapped to the BMW E30 chassis and I assume that the signal from BMW speed sensor is not the same as the Nissan's one. Could I cut this wire ? Will the engine work properly without this signal?

5. What is in the #56 and #57 pins?

6. The #48 pin is a throttle sensor power. Does ECU send power to the TPS or should I deliver power to this wire by myself?

7. There are 2 Throttle position sensor plugs. One is conneted to the ECU and the 2nd one is connected to the plug going to the chassis. None of the 2nd plug wires are connected to the ECU. Is the 2nd TPS plug (this one which connects to the chassis plug) necessary or can I just cut it?

Thank you for your help in advance.

Best regards,
Michael.

[Wiring Specialties]

First picture - black box is the wiper amplifier. It is what causes the int. wiper operation.
Second picture - Late model Skyline ABS wiring.
Third - Chassis interface connector for the EFI harness.

The first two items are not needed. Open up the harness and remove the wiring completely.

The last one is where the work needs to be done.
ON the rest of yoru questions - since this harness has ABS, it is likely to have auto as well. I think you mentioned 2 TPS connectors, right? You will have a lot of ABS and Auto controller wiring going through the chassis interface connector. Looking quickly at the ECU pinout you are using, you should be OK. Just pull what you do not find identified.

Good luck.