Ecu reset how?

Some time ago i replaced by lamda sensor, just a second hand one as my puma had a flat spot.
It improved slightly so i will purchase a new one.


I didn't do anything else but what about the ecu?

Does that have to be reset and how?

Or am i ok to just remove and replace with a new sensor?
thanks.

madonna said:

Some time ago i replaced by lamda sensor, just a second hand one as my puma had a flat spot.
It improved slightly so i will purchase a new one.


I didn't do anything else but what about the ecu?

Does that have to be reset and how?

Or am i ok to just remove and replace with a new sensor?
thanks.

Click to expand...

Nothing wrong with resetting the ecu.
Simply disconnect power, you don't need to but I remove the ecu for about 30 mins, then replace and reconnect power.

Flying Scotsman said:

madonna said:

Some time ago i replaced by lamda sensor, just a second hand one as my puma had a flat spot.
It improved slightly so i will purchase a new one.


I didn't do anything else but what about the ecu?

Does that have to be reset and how?

Or am i ok to just remove and replace with a new sensor?
thanks.

Click to expand...

Nothing wrong with resetting the ecu.
Simply disconnect power, you don't need to but I remove the ecu for about 30 mins, then replace and reconnect power.

Click to expand...

Disconnect the battery or the ecu and if ecu how?
thanks.

Flying Scotsman said:

Personally I do both.

Disconnect battery, so the two terminals to the battery, generally a 10mm socket or spanner will suffice.
Your ECU is locked behind the carpet in the passenger footwell on the side of the car. You should see a little black case that hold the ecu in place. It has two rivets in it that need to be drilled out to remove it. The ecu is attached to the wiring harness by a 10mm socket. Undoing that removes the ecu.

Click to expand...

I understand but rivets that need to be drilled out?
You mean like pop rivets?
It would seem a lot of trouble to drill them out, then have to buy a pop rivet gun to replace the rivets?

If that is the case,i think just disconnecting the battery?
Will that not reset the ecu?
thanks.

Yeah pop rivets, but nobody replaces them.
Yeah disconnecting the battery can reset it.

thanks flying Scotsman, you've been a big help.

Don't forget that once the battery has been off, you need to drive the car for a short while to allow it to re-learn its settings, car sometimes feels a bit "off" for a short while as this is done.

zinc2000 said:

Don't forget that once the battery has been off, you need to drive the car for a short while to allow it to re-learn its settings, car sometimes feels a bit "off" for a short while as this is done.

Click to expand...

Can someone fully explain (or point to an article) this ECU (?) re-learning stuff?

I had a flat battery (bulb left on) so disconnected both terminals and put it on charge for a few hours. It then started first time and I thought that was it, done sorted.

This evening, took her out and just going up the road felt like the choke was fully out (if you remember manual chokes ) It was running so rough I took her round the block so that I wouldn't be too far from home if it packed up. It cleared itself soon enough, but even after the round trip of 8 miles it is not as free revving as usual and is not taking off like a rocket over 4500 revs, as usual.

It sounds OK, just responds like you've got 3 fat blokes as passengers - not sure how you'd get the back two in, but you get the idea.

Is all this part of ECU 're-learning'?

Official ECU reset procedure:
Disconnect battery for 1 hour:

Ford Technical:
After reconnecting battery, engine should be allowed to idle for 3 minutes, as stored idle and drive values contained within the powertrain control module have been lost. This may cause a driveability concern if the following is not carried out.

Once engine reaches normal operating temperature, revs should be increased to 1,200rpm and maintained for approximately 2 minutes. This will allow powertrain control module to relearn idle values. For powertrain control module to complete its learning strategy, vehicle should be driven for approximately 5 miles of varied driving.

YOG said:

Official ECU reset procedure:
Disconnect battery for 1 hour:....

Click to expand...

Many thanks for that.

In your opinion, do the symptoms outlined above sound like it is doing this relearning stuff and not another co-incidental problem? If so, do you think I should press on with normal driving and let it sort itself out or disconnect the battery and follow the procedure you detailed above?

Thanks for the info already.

The engine shouldn't play up like that.
I would start again and follow the correct procedure. If you then still have problems, you probably need to start looking for a different fault.

YOG said:

The engine shouldn't play up like that.
I would start again and follow the correct procedure.

Click to expand...

Thanks, will do.