ECU Reset?

[Roadrunner]

When I had my Subaru Legacy RS-B, there was a relatively simple operation using a couple of wiring connections under the dashboard to reset the ECU back to its original configuration so it would start to "learn" again. This was particularly useful if you'd had a bad batch of fuel and the ECU had adjusted itself to cope and possibly, therefore, reducing power.

A couple of months ago, my car was at the dealer to get a gearbox oil leak fixed and, because it was in for five days, the battery had been disconnected. This, I guess, had the same effect of resetting the ECU INSERT INTO post VALUES (it certainly did on the Subaru) and the car felt much more responsive for a time, until I got my next batch of poor quality fuel. Without a reset, it takes the ECU a long time to optimise for better fuel again and it may never regain its absolute optimum settings.

Short of disconnecting the battery again, does anyone know if there's a simpler method of resetting the ECU?

Brian

[BraindG]

As far as i know, disconnecting the battery for about 30 minutes is the only way..

[Brind]

When you say bad batch do you mean just crap quality super/optimax unleaded fuel or do you mean using basic 95 octane fuel?
I think my car has been running on the basic 95 for a few refills, at least the last two it has 'cos my dad used the car and didn't realise.

I thought the ECU was adjusting all the time? therefore changing live to every situation, 95,97,98 RON fuel.

[-LegnumVR4-]

10sec is all u need to reset the ECU, just disconnect the battery. Thats what the guys at Mitsubishi here do.

[Roadrunner]

Brind,

I was referring to a bad tankful of SUL or Optimax - never use NUL. Doesn't happen very often, but the car knows when the fuel's poor quality. Yes, the ECU is learning all the time but it reacts quickly to poor quality fuel INSERT INTO post VALUES (and, with my Subaru, could even shut the engine down to fail-safe mode) but it takes ages for the ECU to relearn back up to optimum, and may never actually get there which is why it needs an ECU reset to sort. Fail-safe mode in the Subaru meant the turbo boost was reduced by around 0.3bar on each turbo INSERT INTO post VALUES (so, to around 0.5 on the first and 0.7 on the second) which meant peak power down from 270+ to less than 220.

Easy enough to disconnect the battery occasionally to sort it though. Thanks.

Brian

[Brind]

Thanks H.7.

I hope mine has gone into 'fail safe' could see more power.

[chris g]

May not be relevant but on MR2 turbo and n/a you removed the ECU fuse and system reset after a short period of time

NB This is post 100 so I believe I now become a Senior Member and I can now retire to enjoy my dotage and my deteriorating health and limited mobility

so if I do not post for some time its because I have still to master sitting and typing at the PC whilst holding onto my zimmer frame

[Roadrunner]

Congratulations on your promotion, from another old git .... :beerclash

[jaysback]

just had a quick look under the bonnet of mine.
try pulling fuse 11.
looks like the engine magement?