How do I get the sensor turned off?

[savanna]

Hello

A couple of days ago my 940 SE developed a hole in the exhaust. I had the exhaust changed at the tyre specialists, as advised by the patrol officer I called out. I don't know anything about cars (except how to drive it) and didn't know why the engine suddenly sounded embarassingly loud. After the exhaust was replaced, the engine does sound smoother, but I've noticed the sensor (the orange triangle with the little green figure) is still on. I asked the tyre specialist who changed the exhaust why the sensor stayed on and was told I would have to get the engine reset or wait to see if the sensor goes off by itself. Can anyone please advise me on the most economical way to get the sensor turned off? Thanks.

[Chesh740R]

Disconnect the battery for an hour or so and then reconnect. This should clear all the fault codes.

Make sure you know your radio code if you have one before disconnecting the battery.

[Jod T5]

Originally Posted by Chesh740R

Disconnect the battery for an hour or so and then reconnect. This should clear all the fault codes.

Make sure you know your radio code if you have one before disconnecting the battery.

i generally recomend disconecting the battery overnight to reset the ecu warning light, however recently mine reset leaving for only two hours...
cheers
jod

[savanna]

Thank you. I'll have to see if my radio code is among the documents I got from the previous owner.

[Jod T5]

Originally Posted by savanna

Thank you. I'll have to see if my radio code is among the documents I got from the previous owner.

if not you will have to rig up a 12v feed to the radio when you disconnect...
cheers
jod

[Suterman]

Disconnecting the battery for just a split second will reset the lambda light, however if you leave it disconnected for 15-20 minutes or more it will cause the ECU to reset meaning that the car will run richer for a while, you wont notice the difference unless you floor it all the time but I would advise against disconnecting it for any period of time as fuel economy and performance will suffer, if only a small amount.

It will take upto about 3 weeks for the ECU to re-adapt under normal driving conditions.

To encourage any residual charge to die away, and speed up "disconnect" time, disconnect +ve & -ve leads from battery and then connect them together.

Not heard of a car that would run rich particularly after resetting ECU, just won't run to maximum efficiency / performance until the ECU re-learns the engine configuration.

As for 3 weeks... it depends on miles, not time: can take up to 500 miles or so though to re-learn the way you drive the car

To help the ECU re-learn your engine, do some driving at varying engine revs and engine / throttle load conditions.

Pete

[Suterman]

just speaking from experience Ive had with chipping and swapping ecus etc..

[adamsky01]

Originally Posted by savanna

Hello

A couple of days ago my 940 SE developed a hole in the exhaust. I had the exhaust changed at the tyre specialists, as advised by the patrol officer I called out. I don't know anything about cars (except how to drive it) and didn't know why the engine suddenly sounded embarassingly loud. After the exhaust was replaced, the engine does sound smoother, but I've noticed the sensor (the orange triangle with the little green figure) is still on. I asked the tyre specialist who changed the exhaust why the sensor stayed on and was told I would have to get the engine reset or wait to see if the sensor goes off by itself. Can anyone please advise me on the most economical way to get the sensor turned off? Thanks.

ok u have the 940 se the easey way i have found to re set the ecu is to simply pull out fuses no 1 for 15 min no longer or u will u reset every thing
or u can put the pin in to no 3 or 4 im not sure and push the butoun like so 4-4-2-3 but i would not reomend the last only as a last resort
if u want any other help feel fre to email me i have the complete wiring digrames for the 940 / se /t/ glt 240 850 740 c 70 v70 s70 and xc90