E.C.U Information

Associated names are : E.M.S (Engine Management System), E.C.C.S (Electronic Computer Control System), E.C.U. (Electronic Control Unit)

The E.C.U is in charge of the running of the engine - transmitting signals from all the relevant components. To list some : Air Flow Sensor, Injectors, Road Speed Sensor(s), Exhaust temp sensor, Manifold Pressure sensor, Lambda Sensor.

Over time the E.C.U. can improve its performance, but does have a standard set of variables - such as fuel to air ratio, acceleration ratio and air temperature. This is why whenever you fit a new performance part such as air filters, exhausts etc you should do it with the Battery Disconnected. Doing this also prevents The vehicle Earthing out on anything.

Fortunately for us Nissan owners, most of their vehicles have a "self learning" E.C.U. so it can be reconfigured (only to an extent though).

To get your E.C.U. to reconfigure itselt, simply run it until the engine is at normal running temperature, and switch it off at the ignition (take the key out of the barrel),  disconnect the battery Negative cable, and press the brake pedal to use the remainder of power left in the electrical system, then leave it for about half an hour. Re connect the Negative Cable, and go for a "drive" that would represent its new values, it will make a note of them and power will be given as required.

At this level it will handle Air filter and Exhaust modifications without problems. Once you begin upgrading turbo, coils & boost pressures, this is when you need to upgrade the E.C.U. as it cant provide the correct ratios.