I have just bought an Impreza STI version 4 5 door (Type GF8E5ED) and have a couple of queries that I would be grateful for answers to:-

The car has only done 9,500 miles and has, to the best of my knowledge, been run on 95 unleaded with occasional tank fulls of 97 unleaded (if the previous owner has followed the same advice I was given by Lockyear Cars when I bought the car). Having read horror stories about using the wrong octane fuel, I have decided to run the car on 97 (Super Unleaded) from now on. I wish to re-set the ECU to take full advantage of this and intend doing this myself by disconnecting the battery from the car and leaving it for a while for the built in capacitor to discharge. Lockyear cars were not able to do a reset for me!!

1. Will this procedure reset the ECU OK?

2. Is there any downside to carrying out this procedure?

3. How long should I leave the battery disconnected?

4. The car has a 'Subaru Super Integrated Sound System GX-55W' which has a 'Kenwood' logo on the tape player flap. Does this radio have a protected code number that will mean re-entering the number after the battery has been re-connected?

5. The tyres are Bridgestone Potenza SO-1 type. What is the recommended tyre pressure for road use?

Thank you in advance for any assistance you are able to give.

Steve

Hope this will help..

1,This should re-set the ECU ,and I fully recommend you use SUL all the time.

2,There should not be any downsides but give the car a good run as it needs to re-learn all its parameters.

3,Leave the battery disconnected overnight, this should do the trick.

4,Idon't think Kenwood code any of their radios but i'm not 100% sure..(Normally if the front comes off there is no coding).

5,For pressures i would run,32 psi front and 28 rear.(this is something you can play around with yourself.)

Hope this helps!!

Steve,

Check further over the stereo, a lot of Kenwood units definately do require a security code - don't know about yours specifically. I'd contact Kenwood.

Secondly try this I have chopped off Middleton Rally Team webpage (www.mrtrally.com.au) to reset the Impreza ECU without disconnecting the power. I cannot claim to have tried this but the leads do exist under the dash - it is a common mistake for alarm installers to connect together, thinking it is something they have undone which causes the check engine light to come on.

MRT How to Tip
How to re-set your ECU unit.
ECU clear memory procedure is as follows for auto and manual transmissions:

With engine at operating temperature, turn engine off. Place gear shift lever into park (auto transmission cars only)
Locate the two ECU check connectors, for most cars they are located under the steering column and consist of a black plastic male and female connector, and a green male female connector. The exact location of the connectors varies with the different year models, but generally they are located under the steering column on the drivers side.
NOTE: sometimes they are still taped over with some small amount of plastic tape, so look hard, they will be there!
With the ignition OFF connect black to black and green to green.
Turn on ignition, do not start the engine, (and for auto transmission, cycle the gearshift lever from park to neutral and back to park ), depress the accelerator pedal to full throttle and hold for a few seconds, and then release.
Start engine and then drive for at least one minute, keeping road speed above 11 Km/h.
ECU is now re-set.
At this point the check engine light should start to flash the all clear signal (steady 1/2 second interval flashes). If the check engine light does not flash, or indicates some other sequence, there is a fault present in the system, and should be professionally checked for necessary repairs.
Once, stop the car and turn off the engine.
Disconnect the plugs.
Job complete

Steve

I'd do the MRT method, the hardest part is finding the connectors! Mine were in the loom behind the steering column under the dash. Then you won't have to worry about the codes for the radio.

Tyre pressures are on the pillar in the drivers side door.

Good luck, happy motoring http://bbs.scoobynet.co.uk/smile.gif

Justin

Thanks to all of you for your replies to my posting.

I will try the MRT method of re-setting the ECU this weekend.

I have subsequently discovered that the CD in this car does NOT have a security code.

Steve