Engine 850: B5234T/2.3/20v/T5: home made code reader

[bob13]

Jod, Just a quick question if you have a engine management fault does this mean the light will stay on no matter what until you reset it, or does the light go
out once the fault has been fixed. This can't be the case for the ABS as i had the light come one once and havent seen it since. Cheers Bob...

[Jod T5]

Originally Posted by bob13

Jod, Just a quick question if you have a engine management fault does this mean the light will stay on no matter what until you reset it, or does the light go
out once the fault has been fixed. This can't be the case for the ABS as i had the light come one once and havent seen it since. Cheers Bob...

bob a abs fault will appear on is own circuit ie the abs light will stay illuminated orange....
all fault codes triggering the green warning light (lambda light) need to be removed before the light will go out...clearly there is no point in removing the code if the problem has not been reapired or replaced.....
however there are some codes (known as soft codes iirc) that will disappear follwing a lengthy (overnight) ecu removal...1-2-1 maf sensor signal missing is one of these.....
have you built a code reader ?
if not i can outline the simple way using a 12v lamp and some wire and paperclips....
cheers
jod

[bob13]

Yes i have built a code reader have no need for it yet hopefully, but always handy to have.
Just wondred thats all, if you were to get a intermittant fault would the lamda light come on somtimes then go out once the fault self corrects or like you have said the light would have to be reset no matter if fault was still there or not. Like my ABS light did once.
Thanks Jod all the best Bob.....

[Jod T5]

Originally Posted by bob13

Yes i have built a code reader have no need for it yet hopefully, but always handy to have.
Just wondred thats all, if you were to get a intermittant fault would the lamda light come on somtimes then go out once the fault self corrects or like you have said the light would have to be reset no matter if fault was still there or not. Like my ABS light did once.
Thanks Jod all the best Bob.....

the abs light on some models stays on until around 10/15 mph is attained it will then turn off, in my experience some units stay on for 5 seconds or so and then turn off irrepective of vehicle movement.....
i would not expect the abs light to go out "mid journey" although this behaviour could well be down to a loom fault under the fuse box.....
the flasher code readers are a must for all 850 owners...here is a picture of mine.....

cheers
jod

[Lmason]

hello bob,
been reading the thread.
some of the faults which arent considered "severe" by the management system may extinguish the management light itself, without having to read and reset the code. this happened to mine when one of the pipes from the turbo was split a little and leaked. when i replaced the pipe, it gone out itself.
with reference to my original post, my light has come on immediately after disconnecting the maf sensor (someone sugested to do this) and it hasnt gone out, despite diconnecting the battery and ecu overnight for 12 hours.
my fear is that a component may of been damaged after diconnecting the maf sensor.
if i am lucky, im hopeing the management light will go out after reading and reseting the system with the home made code reader i am about to make.
im keeping my fingers crossed, as i am now spent up, after having to get a radiator.due to it springing a leak

[Jod T5]

Originally Posted by Lmason

my light has come on immediately after disconnecting the maf sensor (someone sugested to do this) and it hasnt gone out, despite diconnecting the battery and ecu overnight for 12 hours.
my fear is that a component may of been damaged after diconnecting the maf sensor.
if i am lucky, im hopeing the management light will go out after reading and reseting the system with the home made code reader i am about to make.
im keeping my fingers crossed, as i am now spent up, after having to get a radiator.due to it springing a leak

how do you know the maf sensor is setting off the lambda light?...the wiring on the maf plug is known for being weak.......
connect a 12v bulb 16+ 3-
the bulb will be lit with the ingition off and extinguished with the key at pos11
bridge with a length of wire between 3 and 4 for a period of 1 second and remove the bridge......
the light will flash x-x-x
to reset the code...read the code, then replace the bridge for 6 seconds and remove bridge..the light will flash.... immediately it flashes re inset the bridge for 6 seconds.....then remove
if you have not got a bulb use a 12v multi meter....
cheers
jod

[Lmason]

cos i unplugged it, that is, the maf

[Jod T5]

Originally Posted by Lmason

cos i unplugged it, that is, the maf

i assumed as much......

believe me the maf sensor fault will be extinguished if the ecu is left out overnight...
this is why i am pointing out that either your maf sensor is knackered possably due to faulty wiring in the plug or you have a different separate fault...
cheers
jod

[Lmason]

what usually goes wrong with the maf wiring?

[CTCNetwork]

Hi,

Originally Posted by Lmason

what usually goes wrong with the maf wiring?

From what I have read, the sensor wire in the MAF gets coated in muck/oil and will burn out..
So no wire to sense the air..

Des. . .