Hi All,

My car description is on the left.

I am thinking of doing an ECU reset this weekend to retrain the air/fuel ratio of the car. I know the procedure (disconnect the battery for 10 to 15 min). Here are my questions:

1. Will this erase any updates Ford has applied/installed on my ecu?
2. Any other issues I need to know about.


Thanx

From my understanding (I suggest second opinions) the updates are applied as "firmware" which are hard written into the ECU. what you are resetting is purely the "short term memory" of the ECU. When you do the reset, the car starts afresh, looks at how hard your putting your foot down, the general driving practices, and fluctuates the air / fuel ratios. so it will not remove any updates Ford have applied.

As for other issues, there arent any. I used to do this regularly on my Focus (description below) and never had any problems but always saw an improvement in MPG.

After I have reconnected the battery terminals after around 20 min I noticed the following:

1. The clock and preset stations were not lost (the radio did ask for code though)
2. Everything on the car computer was lost except for the trip mileage (the one that can be reset)

Is that normal behaviour?

It is because you are resetting its "short term memory" - that includes the resettable odometer, average MPG, and range estimations etc.

The radio does always ask for the code after a reset, this is incase some theiving wretch takes your radio away - they have to disconnect it from the battery so it prompts for the code. It has its own long term memory inside, which is where the Radio code, and the radio settings / features / presets are all saved.

The actual features of the trip computer will not have been lost (I hope anyway??) just the values that it was at previously. so if you reset the car with a reset ODO reading of 120 miles it will not say that the ODO is 0.0

When I did the ECU reset it had V-Power in the tank (3rd consecutive tank). I take it that when the reset was done it had adjusted my driving style, air/fuel ratio, etc according to what the car has in the tank. If I am to fill up with regular unleaded will it cause any problems?

Yes and No, Yes the engine will adjust to what it is using - higher grade fuels will require less injection, and will still give optimum performance. obviosuly a higher premium fuel will have benefits, and will improve the drive, however filling up with a different grade of fuel (be it shell standard, or tesco's own unleaded) will not cause any problems.

as silly as this sounds - think of it as getting drunk.

You buy a high price bottle of wine with a high alcohol content. You may only need to drink one bottle and you can be as drunk as if you bought the corner shops budget 0.001% cider. Only difference is, you would have had to drink a lot more cider than you did the wine.

You dont have any problems, as your hangover will still be a hangover regardless...