# Check Engine light not working



## Jasmine (Jul 18, 2014)

Hi,
I need help
I have a 97 Pathfinder 4X4
The check engine light does not come on when i start the car. all of the other lights around it come on except the ATP light (which im not quite sure what thats for) i checked the bulb and its ok. i switched it around with working bulbs and still nothing. I do have codes so i know it should be on but its just not working. ive been searching the internet for someone with a similar problem but no luck. I did just buy the car used so im guessing they did something to it so i wouldnt see the light when i bought it but i need to fix it asap. i cannot pass inspection without it. PLEASE!!!! if anyone has any input it would be greatly appreciated. Thanks!

Jasmine


----------



## smj999smj (Jan 1, 2006)

With the key "on," check for power at the white/black wire. If there is no power, check 10A fuse #7 in the fuse block. If there is power and the bulb is good, then you either have a bad ground circuit or bad ECM. Unplug the ECM and check the orange wire from the MIL socket to pin 18 of the ECM harness connector. Check for continuity and check for short to ground. If the circuit is good, check the ECM grounds. If those are good, plug everything back in and recheck. If it still doesn't work, replace or repair the ECM.


----------



## Jasmine (Jul 18, 2014)

So I don't know much about wiring. But I checked all the fuses and they're good. Where do I find the black and white wire? To the ecm? I plan on checking the ecm in the morning but I'm not quite sure what I'm looking for unless there is an obviously bad wire.


----------



## Jasmine (Jul 18, 2014)

Is the ECM and PCM the same thing?


----------



## smj999smj (Jan 1, 2006)

Jasmine said:


> Is the ECM and PCM the same thing?


PCM, ECM, ECU, ECCS control unit are all acronyms that all refer to the engine management computer. The white/black wire (white wire with a black stripe) is at the bulb socket for the MIL, which one would have to remove the instrument cluster to access. Power runs to the MIL bulb socket, though the bulb, then to the ECM, which grounds the circuit for the bulb check or when there is a stored code.


----------



## Abelsathekge (Aug 30, 2021)

Hi...
I have almost the same problem on my Np300 ka20

It cranks but no start.
When i check for spark from the distributor, it is absent on all 4 of them.

And when i term the key on, all the dash lights go on except the engine light.
Please help


----------

