How do you reset the ECM?

Hello,

The ECM is located under the dash, just right of the gas pedal.

If the ECM just needs to be reset, you will have to go through a procedure. Some of these can be done manually, others will need a special scanner.

Try the method below:
Turn the key to the on position (do not start).
After 3 seconds pump the accelerator pedal 5 times
After 10 seconds hold the accelerator pedal to the floor for 12 seconds.
Release pedal, wait 10 seconds.
Hold the accelerator pedal ageing to the floor for 10 seconds.
Turn ignition switch to the Off position.
Wait for 10 seconds and then start.

This should reset the ECM.

This method works if you are just trying to reset the ECM.

Please let me know if you have any questions.
Thank you.

Yes, we needed to reset it.
We have a crank but no start problem.
according to the Mister, he has replaced the fuel pump, distributor, spark plugs, battery, booster, timing, and ECM. fuses, relays, and sensors checked. All are working fine. still cranks but no start. there is spark. Also, he says the first gauge meter doesn't work, is that part of the reason why it doesn't start up? Thank you for your time and help.

I have minor comprehension problems because English is my second language.
Can you please show a picture of what the ECM switch looks like on the ECM, and a picture of where it is, facing which direction, etc. Because the Mister read it somewhere about a reset with a switch. I have to assist to comprehend and translate to the Mister. Thank you for your time and help.

Hi,

First, your English is excellent. However, what you are asking doesn't exist. There is no ECM switch.

Let me see if I can get you going. First, you indicated there is spark to the spark plugs. I need you to try something. See if the engine will start for a couple of seconds and then stall if you use starting fluid.

Try that. If you are getting spark, it should do what I indicated. If it does, then we know it is related to the fuel system.

As far as the ECM, it is basically a computer module. It runs based on programming from the manufacturer. It can be what is called "flashed or refreshed" but that will require a scanner that can perform the reprogramming.

If nothing was done with the ECM, it should be fine.

Let me know what happens when you try the starting fluid. If there is no change whatsoever, then I need you to reconfirm the ignition spark to the plugs. Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Let me know what you find or anything additional you can think of that may help me diagnose the problem. For example, were any diagnostic trouble codes found?

Take care,

Joe

Thank you.
Last update, I was told that the spark was weak. Found the crankshaft sensor not connecting. We have a new sensor, but we also need the harness connector. Got the connector. Now we don't know how to connect the connector and sensor. the color wire of the connector is both black we don't know which one goes to with what? please help.
And with the starting fluid, he said it didn't work. well maybe when we do get the sensor connected, then we'll see what is next.

As far as the code part is concerned, we don't have that tool.
The ECM was swapped out from a 2004 Frontier.

Hi,

I attached two pics below. The first shows the sensor wiring. One wire is blue, and one is black with a white tracer.

If you look at pic 2, it shows which pin is number 1 and number 2. When you wire the new connector, place the blue wire to pin 1 and the black/white wire to pin 2.

The black/white wire is a low reference wire that provides ground. The blue wire is a signal wire.

Now, the biggest concern is the new ECM. It may or may not work. These are designed to operate specifically to certain designs. There are differences between the two model years. Why do you feel the original ECM is bad?

Let me know.

Joe

See pics below.

installed the sensor and connector.
We did the above steps to reset the ECM.
The spark was strong, still didn't start.
Where are we supposed to spray the starting fluid?

Hi,

You need to spray it into the throttle body. From the air filter box, there is an air induction tube that runs to the throttle body. That is where to try it.

If it is possible, record it cranking and upload it for me to hear. I may be able to point you in the right direction for repairs.

Joe

Aloha, sorry for the late update due to wet weather.
Right now, we are working on wiring.
We need help in connecting the engine room harness from a 2001 Nissan Frontier to a 2002 Nissan Frontier. I am still having problems understanding or reading the wiring diagram, I mean if it being explained from somebody else, I probably would have more understanding of it. Confusion with the colors and different types of white stripes being solid to spaced, and no white stripes. Noticed that day 2001 harness has more wires than 2002, so I don't want to be connecting the wrong wires.
Thank you for your time and help.

Hi,

If I send you the schematics, you'll want to hit me. LOL, I have a question before I proceed. Why are we switching the harness? The 2001 is more involved and if you are not familiar with wiring schematic, it's going to be difficult.

I have the schematics for both model years if needed. Let me know exactly what is being done and why. Hopefully, I will have an easier way for you to do this.

Take care of yourself,

Joe

our original harness was corroded, and all broken up, so the Mister got the 2001 one.

I do too have them, but I just needed a better way of it being explained simpler.

Hi,

I will try my best. If you have the schematics already, what is confusing for you? Let me know as much as you can.

Joe

Just to jump in on this. Are you looking for a way to understand how to read the wiring diagrams or are you trying to understand why they are different?

Basically, the way you read these diagrams is you find the connector that you are working with on the vehicle and then match that up to the diagram and it shows you where the wire goes. Then you locate that connector, and you will find the same wire in that connector.

However, if you are trying to use a wiring harness on a different vehicle that is not the same then you are going to spend more time re-wiring the replacement harness than it is worth.

You are going to have to remove any wires that are not used on your vehicle and add those that are, and the wiring colors will never match up because these are different harnesses.

So, if you want the wires to match on these different harnesses then they never will.

I think the best suggest we can make is not to use this harness and use one off of the same vehicle you have.

If that is not an option, then you are going to have to add and remove wires to this harness to make it the same as what you have but that is a very large and confusing project.

Thank you very much for that. makes very sense. We're stuck right now because of trying to understand the wiring diagrams and trying not to frustrate at the same time patience is also running low. but thank you so much for explaining it that way to me. but to answer your question I was wanting to understand more of how to read the diagrams.

Good morning,

Just to add to all the answers, I attached a YouTube video explaining how to read wiring diagrams for you to view.

Let us know if you have any other questions.

https://www.youtube.com/watch?v=ZHrJOB14lwE

Roy

Thank you very much for your help.

You are welcome.

We are always glad to help.

Let us know if you have any more questions.

Roy