I have a problem with my engine management light but there is a bit of a story with it,anyway i bought my car about 3 years ago from a trader.On my way home the EML came on so i phoned the trader and he said take it to his auto electrician which i did 3 times as the light kept coming back on.At this time i knew less than nothing about my car and hadnt even discovered this club but on the first visit he read the code and ordered parts,second visit he changed the left hand sensor on the manifold and on the 3rd visit he took the storage compartment apart behind the passenger seat and messed with wiring in that area.Afterwards the EML stayed off which i thought the problem was fixed,my EML comes on and goes off with the ignition like it should but my suspicions the the EML isnt working were first raised when i had some issues with my timing chain and the engine was missfiring but no EML so having recently bought a ODB code reader i plugged it in to discover i have a PO141(post cat sensor faulty) pending so i cleared the code,drove the car a few times and the code has come back on the reader but no EML so i am wondering what the auto electrician has done to disable the EML so it comes on/off with the ignition but not with faults?
P.s how long does the wire have to be for the 3rd sensor?
I believe that if the code is just pending, it doesn't turn the light on.
Not sure if they can disable the CEL but still have it correct come on as test when you turn the ignition on without some sort of electronics beeing added!
actually, I bet they could hook the bulb it up to the battery charging light, that would cause it to light up on ignition but turn off once the engine is started.
Heater Circuit Malfunction (Bank 1, Sensor 2)
Before changing the sensor, check the wiring on the harness to see if there is a loose connection, there is either a loose connection on the harness or the sensor has an internal short and needs replacing.
This being the case it will cause the code.. but it has to detect the fault on 3 occasions (full cycles in a row?.. correct me if I'm wrong) and untill it does the EML won't light up, I also confirm that "pending" codes don't cause it light up.
What does the "pending" mean?
In this case "pending" is an adjective.. a description...
imminent / Not yet decided or settled; awaiting conclusion or confirmation.
The error has been detected but the ECU is waiting to deceide if it is anything or nothing.. this is why it has to detect the same error over 3 full cycles before lighting the EML, pending codes can clear themselves if the error isn't reported again and as such there is no need to worry too much about them.
Is there a way of safely making the EML light come on for testing by disconnecting a o2 sensor or something?Also how long is a cycle?
Bry you could unplug the post cat sensor, the plug for which is behind the n/s tail light. this will be ok as it doesn't affect tune but reports that sensor is US. don't forget to take the car out for 3 good runs and the EML should light up like its Christmas.
I'm not sure exactly what time/distance a "ccle" refers to either.. but as E has said, take the car out for a wee drive.. say 20 minutes or so, 3 drives like this should throw a cell if an error is detected. (the 20 minutes may even be enough for the full 3 cycles.. I've no idea)
Ok bit of an update on this:
I have been running with 3rd O2 sensor disconnected for about 350 miles to provoke an EML but didnt show(code reader says 1 fault and 1 pending) so i have removed paneling behind the passenger seat and i think i have found what he has done.It looks like he has cut the yellow/red wire near the ECU and spliced it onto a black/red wire with the plastic protective tube around it(see pics).I have included pics of all the wiring in that area so if there are any electrical experts that can spot anything else and verify my theory please let me know i'm right.Thanks in advance,Bry.
Yellow/red wire cut near ECU:
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/005-12.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/004-14.jpg)
Yellow/red wire spliced to black/red wire in plastic tube:
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/008-9.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/007-9.jpg)
Pics of all wiring in the area:
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/011-6.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/010-5.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/005-12.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/009-7.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/001-8.jpg)
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/002-16.jpg)
in the library there is a 2zz swap wiring table
it should show you what the relative wires are
(http://i370.photobucket.com/albums/oo149/bryanstorm-2008/005-12.jpg)
you can see which pin it is so it probably easiest to look at the plug and count the pins. Then we can look up what that wire is on the ECU ?
Am i right in thinking i just un-splice and reconnect the yellow/red wire and it should be fine?Are there any dangers to this with it going into ECU?
I'd touch nothing until you confirm what the wires actually are
Yellow/red should go direct from ECU (Pin 15, connector E2) to the cluster via splice IC2 (I forget where that is).
Black/red is generally a switched live - there are a lot of them off the ECU, but I wouldn't mind betting it goes to pin 8 on connector E2 (IGSW, switched live).. But it could be any one of half a dozen wires, so it'd be interesting to see which plug that goes to.
On the plus side, there's only one Yellow/red from the ECU, and it's the warning lamp wire.
[edit] E2 is the upper-most black connector, pin 15 is the lower-most on the center row of wires.
Quote from: "muffdan"actually, I bet they could hook the bulb it up to the battery charging light, that would cause it to light up on ignition but turn off once the engine is started.
Looks like that was a good call Jason.
Quote from: "E"Quote from: "muffdan"actually, I bet they could hook the bulb it up to the battery charging light, that would cause it to light up on ignition but turn off once the engine is started.
Looks like that was a good call Jason.
You were spot on Jason,i rejoined the yellow/red wire and EML stayed on so i cleared it and went for a drive and 12 miles later it has returned so my EML is working just need a sensor for the P0141.
hmm unscrupulous.
A guy here just brought a car and has found tape over the em bulb. s:? :? s:?
Quote from: "philster_d"hmm unscrupulous.
A guy here just brought a car and has found tape over the em bulb. s:? :? s:?
Happens all the time - my first Nissan had a permanent gearbox fault (it was an autotragic).. Of course I didn't know that at the time, because someone had removed the bulb from the cluster..
It might be three years since you bought it, but I would still be documenting this and reporting it to trading standards. s:evil: :evil: s:evil:
definitely be trying to do something about this. It's not right, something major could have gone wrong in that time and you wouldn't have known.