V7STi Posted January 20, 2021 Report Share Posted January 20, 2021 Hey guys this is my first time going at it on my own so go easy on the dumb questions. I have a 2002 STi. I am in the process of installing a G4x plugin. I've run all the wires for my additional sensors, just looking to clarify a few things so I don't screw it up. So far I have: Can-lambda, Oil pressure, Oil temp, Fuel pressure, Map Sensor, IAT, flex fuel sensor. Have I got this wiring correct? (EX=expansion harness) Can-lambda ---> can2 (using can1 future) Oil pressure - -> (EX)input- volt6- - (EX)5v & GND Oil temp. ----> (EX)input- volt7- - (EX) GND Fuel pressure -> (EX)input- volt9- - (EX)5v & GND Map Sen ------> Tap ecu har. Sensor to pin B-8- 5v-B9? GND??D8/9? IAT. -----------> Tap ecu pin B27?- - GND?? A7/A15/D8/9? Flex sensor. --> Sen. Not sure- +12v=D2/3? GND? Do i need a second expansion harness to connect to DI's? Hopefully this makes sense Feel free to add in anything extra I might be missing. Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 20, 2021 Report Share Posted January 20, 2021 It would probably make your life easier if you did get a second expansion loom. 40 minutes ago, V7STi said: Can-lambda ---> can2 (using can1 future) Correct. 40 minutes ago, V7STi said: Oil pressure - -> (EX)input- volt6- - (EX)5v & GND Correct, any AN Volt is fine. 40 minutes ago, V7STi said: Oil temp. ----> (EX)input- volt7- - (EX) GND For a temp sensor it is easier to use an AN Temp input. There is AN Temp 4 on the other expansion port. To use a AN volt means you need to add an external pull-up resistor which may be a challange depending on your skill level and what gear you have. 40 minutes ago, V7STi said: Fuel pressure -> (EX)input- volt9- - (EX)5v & GND Correct, again anu AN Volt input is fine. 40 minutes ago, V7STi said: Map Sen ------> Tap ecu har. Sensor to pin B-8- 5v-B9? GND??D8/9? Easiest option for this is to just cut the plug off the existing factory map sensor and connect the new one in its place. 40 minutes ago, V7STi said: IAT. -----------> Tap ecu pin B27?- - GND?? A7/A15/D8/9? You have quite a view ways to do this. See section 1.4.2.1 of the manual, it explains the options reasonably well. B27 or D14 would be good options - or if you dont think you will ever be putting it back to stock again then you can cut the maf plug off and connect the IAT to those wires (already has AN Temp 1 and sensor ground wires in that plug). Sensor ground is pin B19. 40 minutes ago, V7STi said: Flex sensor. --> Sen. Not sure- +12v=D2/3? GND? Yes, flex sensor needs +12V (ignition switched), a DI and ground. Doesnt necessarily need to be a sensor ground for flex sensors either (chassis ground is fine). Pinout for the sensor is in the help file. Quote Link to comment Share on other sites More sharing options...
V7STi Posted January 20, 2021 Author Report Share Posted January 20, 2021 16 minutes ago, Adamw said: It would probably make your life easier if you did get a second expansion loom. Correct. Correct, any AN Volt is fine. For a temp sensor it is easier to use an AN Temp input. There is AN Temp 4 on the other expansion port. To use a AN volt means you need to add an external pull-up resistor which may be a challange depending on your skill level and what gear you have. I'll just buy a second expansion loom and use a AN Temp (although i was under the impression the ecu had internal pull ups, if you could fill me in on the correct use of them (for learning)) Correct, again any AN Volt input is fine. Easiest option for this is to just cut the plug off the existing factory map sensor and connect the new one in its place. I'd like to keep the factory plugs intact (not that i need to but you know) and ive already plugged and run new wires to splice at the ecu, im using the Link 4 BAR sensor 16 minutes ago, Adamw said: You have quite a view ways to do this. See section 1.4.2.1 of the manual, it explains the options reasonably well. B27 or D14 would be good options - or if you dont think you will ever be putting it back to stock again then you can cut the maf plug off and connect the IAT to those wires (already has AN Temp 1 and sensor ground wires in that plug). Sensor ground is pin B19. Yes, flex sensor needs +12V (ignition switched), a DI and ground. Doesnt necessarily need to be a sensor ground for flex sensors either (chassis ground is fine). Pinout for the sensor is in the help file. Again ill just get another expansion loom and wire to that for DI, im assuming D2/3 is fine? my understanding is thats what the CAN-Lamda is asking for when referencing the preferred method? Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 20, 2021 Report Share Posted January 20, 2021 50 minutes ago, V7STi said: I'll just buy a second expansion loom and use a AN Temp (although i was under the impression the ecu had internal pull ups, if you could fill me in on the correct use of them (for learning)) The AN Temp inputs have internal pull-ups. (AN Temp 1 and 2 have configurable pull-ups, AN Temp 3 & 4 have fixed pull-ups). You need a pull-up to form a voltage divider circuit which converts the sensors variable resistance in to a variable voltage that the ECU can read. The AN Volt inputs do not have pull-ups fitted. 50 minutes ago, V7STi said: Again ill just get another expansion loom and wire to that for DI, im assuming D2/3 is fine? my understanding is thats what the CAN-Lamda is asking for when referencing the preferred method? Yes D2/3 would be fine for the Flex sensor 12V. For the CAN lambda, D2/3 (efi relay) would be the "Alternative" wiring diagram, so you should add the 22uf capacitor if you use that. The "preferred" method would be a separate relay only used for the lambda, which gets its power direct from the battery. Quote Link to comment Share on other sites More sharing options...
V7STi Posted January 21, 2021 Author Report Share Posted January 21, 2021 forgive me for so daft, wouldn't D2/3 be main 12v from the relay? the way i read the pinout A6 was the main relay coil/control? Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 21, 2021 Report Share Posted January 21, 2021 The diagrams in the quick start guide are newer than the full manual. Notice the relay in the preferred diagram has only the lambda connected to it, the diagram labelled alternative shows the lambda getting power from the ECU relay (which will also have many inductive devices connected to it such as injectors and idle valve etc). Quote Link to comment Share on other sites More sharing options...
V7STi Posted January 23, 2021 Author Report Share Posted January 23, 2021 too easy, all makes sense now. Thanks for that Adam Quote Link to comment Share on other sites More sharing options...
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