Forum » EFI Wiring Fundamentals » Functions of oem ecus compared to stand alone ecus

Functions of oem ecus compared to stand alone ecus

EFI Wiring Fundamentals

Discussion and questions related to the course EFI Wiring Fundamentals

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So by now I watched the wiring fundamentals course and it was very good at explaining the basics of how the electrical system on a car works and its major components.

I own a Peugeot 306 GTI that has a Rotrex supercharger conversion. The car is running on the oem ecu which is a Magneti Marelli MM1AP where an Eeprom socket has been added. The engine XU10J4RS is NA in its standard form. I use my car as a daily driver and occasional trips to the Nürburgring.

My question is if I was to make a new wiring loom from scratch to use let's say an AEM EMT 4 (the cheapest of the AEM range) would this ecu be able to still give me all the functions of the original dash and central locking? Warning lights, odometer rpm and speed in addition to wideband afr, boost and other useful data when going forced induction on a previously NA.

As said I'm new to the whole electrical side of cars and how it works, so bare with me if I'm asking dumb questions.

Thank you guys in advance

Marco from Luxembourg

G'day Marco.

I'm not familiar at all with the inner workings of a 306GTI unfortunately, I haven't had the opportunity to work on one. What year is yours?

You'll need to determine how many of the functions you're worried about are controlled by the factory ECU. On older cars its common for the gauge clusters to have their own sensors for their readings (coolant temp, oil pressure, etc). Often they barely interface with the ECU at all. Controlling the A/C shouldnt be a problem, most aftermarket ECU's are capable of this.

I'd be surprised if the OEM ecu had anything to do with the central locking, but its not impossible. Are there any factory service manuals with reliable wiring information you can look through?

Hey Zac,

Thank you for the reply. My car is from 1997 and I'm in the process of buying official Peugeot Workshop manuals online where I should have all the wiring plans and so on. AC won't be an issue ass it was ditched and replaced with the supercharger.

I'm currently studying the PDF I attached which is a pinout of the original ecu.

I'm just wondering if the AEM EMS4 will cover all the outputs I need and offer the tuneability I'm after. As of now there seems to be only one tuner that can provide a bespoke tune for these conversions, this tuner has developed the conversion together with the shop who offers this service. So if I want to get my car fine tuned I have to travel to the UK for him to do a live tune on my car to suit my mods.

When you buy the DIY kit you get an unlocked oem ecu with a generic map to get the car running. My Var made about 240bhp on the flywheel last time I dynoed it.

Thanks in advance


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