Had a speed sensor code for years. Finally fixed it, went to reset the ECU, nada. The light never blinks when I check the codes, can't reset it, can't make it go away. Ran ODB scanners and it shows as no faults. Tried reseting with OBD scanners as well, nothing. The light will not go away and it will not blink or anything. What's going on folks?

 

take out your cluster, remove the CEL bulb and run a scan on your car once a month.

 

wow, you're lucky I want answers cause you'd be getting lit up for that comment...

 

Did you try the ECU reset method?

 

yes, tried everything fellas. I'm just trying to find out what it could mean.......

 

Id guess there is a short or something in that line tripping the light to stay on constantly, most likely somewhere in the cluster. Have fun with that one.

 

try the disconnecting battery and see of the light still remains lit instantly.

leave it off overnight

 

thats actually quite illegal. technically you can go to jail if caught doing that (well maybe not jail, but a ****load of trouble and probably a hefty fine).

 

dave did u try a different ecu?

 

Guess Im looking at life in prison

 

thats what electrical tape is for... why remove parts when u can just cover it up:P

 

hey, you know what, i put a picture in front of my cel when i went through emissions last time.

 

Don't have access to another ECU.

Another question..


I know that the m56 and f102 are the connectors, male and female. What are the small boxes with 1 and 5 in em? What do they represent? I know the dotted line is a optional circuit/connection? Could I just run 2 wires from the gauge straight to the speed sensor or would that cause the CEL to stay on?

 

The 1 and the 5 are the terminal numbers in the mating connectors (M56/F102) where the engine control harness plugs into the main dash harness.

 

yeah, figured that. So, in theory, me running a new set of wires from the cluster to the speed sensor should be no problem since that's pretty much how they are ran from the factory? It cleared the code and all but why the hell is the light on? I don't even know if they'll let me take an emissions test with the light constantly on...

 

Probably not.

The FSM gives several possible explanations for the constant CEL ranging from a low battery to an internal problem with the cpu (inside the ecu).

You are sure that screw is fully CCW, eh?

 

yeah, tried it many times. If it wasn't constantly snowing for the past two days I'd go out and cut the new wires to see if that helps.

 

alright, so I cut the new wires and the cel is ok again. Now, what I'm guessing I did wrong was that I spliced into the existing wires. I guess I should've completely eliminated them from the circuit. Don't know what it could be besides that. I'll know in a few hours.........

 

Ok, bypassed the old wiring completely and the CEL is back to normal. Thanks eng92.........

 

nice work dave

 

Wow, glad you guys found the source.

 

yeah, makes no sense why that would be the cause of it. I left the splices at the cluster and just cut out the old wires in the engine bay............

 

hahaha, oh man. NOw my speedo doesn't work. WTF?

 

.......

 

seriously
I'm guessing it's cause the new wires are spliced right between the speedo and the old wires which are cut. So, I'm guessing the current is taking the path of least resistance and I have to get back to the cluster and completely remove the old wires from the circuit.......

 

ok, so, what does that damn optional circuit do? I just removed all of the old wiring and now the check engine light never comes on, even when I put the key to on.

 

yeah fixed it yesterday and I could've sworn I posted about it. I don't know what happened. ANyway, nissan decided to put two grn/blk wires behind the cluster to confuse the **** out of me. The one I was using was the cel circuit wire. It was close to the other wire I had to use so go figure. Turns out the grn/blk wire I had to use was the one all the way across the cluster. Figures..........

 

i reiterate

.....

 

tell me about it. Now, my tach is going crazy but thsi was a problem for the past few weeks. While driving it'll just start going crazy, the needle will jump around, jump to a high rpm, or just not do anything.........

 

Oh you needed help

 

No mr. patel. Ha, asking for help in the 4th gen forum? Are you mad? I was just typing what I was thinking and it ended up being a thread. Figure it out myself, like always.

 

but.!.!.!.!


sounded like a cry for help to me!

 

I mean you shoulda just pm'd me to save all this nonsence

 

true. So, the code is back. I'm hoping I just reversed the wires which I'm sure didn't happen, or that the speed sensor is bad, which most likely isn't the case cause it's brand ****** new. Could the sensor go bad from only one wire getting power to it? No right? Open circuit=no current?

 

Correct. I'd just double check the wires.

 

****. I checked the continuity right before putting it all back together. It was all fine. Dammit, I can't catch a damn break......