resetting ECU

Dog_Book · Feb 19th, 2009, 23:49

Ive heard you can reset the ECU by disconecting the battery over night. Is there a faster way of doing this? i read that also it can be wiped by disconecting the battery while the ignition turned on. Woudl this be quicker and not damage it? i want to do this as i have no code reader and want to reset it incase there was anything the ecu was doing to limit anything it shouldnt be. Then ill be starting from a level. thanks

myatt1972 · Feb 20th, 2009, 00:07

I got a U380 code reader on e-bay fairly cheap, works well on my phase 2 t4 and on my mates 98 t5, should work on yours. Much better to read the codes than just wipe them.
Keith...

Dog_Book · Feb 20th, 2009, 18:18

Cant read em like that cosits the OBD version ;/

beemer · Mar 21st, 2010, 19:58

Disconnect the battery
Connect the two battety leads together (NOTE - THE LEADS NOT THE BATTERY!!!)with a jump lead or piece of wire.
Turn ignition key to on & leave for 15 minutes.
Turn ignition off.
Reconnect battery.

bongo · Mar 21st, 2010, 23:09

it may need to re learn its values after batt disconect so you may have eratic idle i will tell you how if so, its been posted before

grass hopper · Mar 21st, 2010, 23:26

usually removing the fuse for the ECM for 1 hour will reset the adaptation.

westville · Mar 28th, 2010, 11:04

Hi
Does re-setting cause any problems, and will it re-set warning lights? We have acquired a V40 1.8 petrol and the airbag light is on, occasionally the immobiliser light also comes on but does not seem to affect the running etc.

beemer · Mar 30th, 2010, 11:36

It will initially clear warning lights but if the underlying fault still exists tey will illuminate again

kirkcairns · Apr 19th, 2012, 15:56

Hi Guys,

Does this actually work?

I need to reset the check engine light to start from fresh, I have OBDII / EOBD readers and I cannot read the faults on the ECU.

Car seems to drive ok has issues accelerating from 60 - 70mph after visiting a garage to change tyres and what they called a free car inspection however I couldnt see what they were doing under the car.

I'm hoping this will be a loose connector in the end (something the garage has pulled out) and nothing serious.

Thanks in advance guys

Sharpley · Aug 30th, 2012, 15:03

Quote:

Originally Posted by bongo

it may need to re learn its values after batt disconect so you may have eratic idle i will tell you how if so, its been posted before

my volvo 2002 v40 2.0 has irregular and high idling. the battery was disconnected before i got it cause i had to get the radio code from the agents. now it shows the SERV light and the "engine" light and sometimes a thick uppointing arrow light between the above mentioned lights. how to sort this out? how how how?

Feb 19th, 2009, 23:49	#1
Dog_Book Idiot Last Online: Apr 21st, 2019 17:29 Join Date: Nov 2006 Location: Derby	resetting ECU Ive heard you can reset the ECU by disconecting the battery over night. Is there a faster way of doing this? i read that also it can be wiped by disconecting the battery while the ignition turned on. Woudl this be quicker and not damage it? i want to do this as i have no code reader and want to reset it incase there was anything the ecu was doing to limit anything it shouldnt be. Then ill be starting from a level. thanks __________________ Vectra VXR estate convert Experience = V40 1998 2.0 CD lots of mods Busy pestering the poor sods here now

Feb 20th, 2009, 18:18	#3
Dog_Book Idiot Last Online: Apr 21st, 2019 17:29 Join Date: Nov 2006 Location: Derby	Cant read em like that cosits the OBD version ;/ __________________ Vectra VXR estate convert Experience = V40 1998 2.0 CD lots of mods Busy pestering the poor sods here now

Mar 21st, 2010, 23:26	#6
grass hopper Premier Member Last Online: Mar 18th, 2011 13:38 Join Date: May 2009 Location: grassmere!	usually removing the fuse for the ECM for 1 hour will reset the adaptation. __________________

Feb 20th, 2009, 00:07	#2
myatt1972 Senior Member Last Online: Dec 28th, 2023 01:04 Join Date: Nov 2008 Location: stafford	I got a U380 code reader on e-bay fairly cheap, works well on my phase 2 t4 and on my mates 98 t5, should work on yours. Much better to read the codes than just wipe them. Keith...

Mar 21st, 2010, 19:58	#4
beemer Member Last Online: Dec 2nd, 2021 16:18 Join Date: Nov 2009 Location: Essex	Disconnect the battery Connect the two battety leads together (NOTE - THE LEADS NOT THE BATTERY!!!)with a jump lead or piece of wire. Turn ignition key to on & leave for 15 minutes. Turn ignition off. Reconnect battery.

Mar 21st, 2010, 23:09	#5
bongo mitsy V40 Last Online: Apr 8th, 2010 01:45 Join Date: May 2009 Location: macclesfield	it may need to re learn its values after batt disconect so you may have eratic idle i will tell you how if so, its been posted before

Mar 28th, 2010, 11:04	#7
westville Resting between Volvos Last Online: Sep 9th, 2021 16:46 Join Date: Feb 2010 Location: Gateshead	Hi Does re-setting cause any problems, and will it re-set warning lights? We have acquired a V40 1.8 petrol and the airbag light is on, occasionally the immobiliser light also comes on but does not seem to affect the running etc.

Mar 30th, 2010, 11:36	#8
beemer Member Last Online: Dec 2nd, 2021 16:18 Join Date: Nov 2009 Location: Essex	It will initially clear warning lights but if the underlying fault still exists tey will illuminate again

Apr 19th, 2012, 15:56	#9
kirkcairns New Member Last Online: Jul 17th, 2012 15:04 Join Date: Mar 2012 Location: Leigh	Hi Guys, Does this actually work? I need to reset the check engine light to start from fresh, I have OBDII / EOBD readers and I cannot read the faults on the ECU. Car seems to drive ok has issues accelerating from 60 - 70mph after visiting a garage to change tyres and what they called a free car inspection however I couldnt see what they were doing under the car. I'm hoping this will be a loose connector in the end (something the garage has pulled out) and nothing serious. Thanks in advance guys

Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)