Shrout1

So my NATS is back on again after the car sat in a low power state for a few weeks (left on business). Solid red "security" light and no crank when trying to start. The alternator is dying / dead - doesn't put out high enough voltage to consistently charge the car. I recharged the battery and have a remanned Hitachi alternator that I will be swapping in as soon as I get the keys added back to the ECU.

I'm concerned that if I disconnect my battery the ECU is going to lose the dealer programming and forget my keys again. How does the ECU store keys that have been programmed in its memory? Is it NVRAM? Does it have an internal battery that keeps RAM alive between battery disconnects? Is there anything I can do to try and avoid this happening in the future?

Used forum search and the Google to try and figure this out but details have not been forthcoming.

Violator

I think without enough voltage present the system can't read keys while cranking. There is an "escape from lock mode" procedure

1. Turn ignition switch OFF.
2. Turn ignition switch ON with registered key. (Do not start engine.) Wait 5 seconds.
3. Return the key to OFF position.
4. Repeat steps 2 and 3 twice (total of three cycles).
5. Start the engine.

The keys are written to non-volatile memory. "Forgetting programing" is usually a hardware issue I believe. Nissan data scan is worth the money, pays for itself if you ever have to program a key

Shrout1

Thank you for the suggestion! I actually fully charged the battery before trying to start the car. The battery was out of the car for about 24 hours in my garage.

And I will look into Nissan data scan - thank you!

Shrout1

Ok questions on the consult connector:

What kind of cable do I need in order to connect to the consult port? I dug up a "14 pin consult connector" on amazon for $40:


Would this allow me to interrogate the ECU through the port?

Here is a link to Nissan Data Scan II - which says that it can reprogram keys on the 99. Also a tutorial with a video of someone adding keys to a 5th gen Maxima (which apparently has the same version of NATS)

Violator

Yeah I'm a little confused here because the 95-99 is listed on their site for NDSI but another site has a guide for NDS2 programming and lists it for 99-03 models. Might wanna shoot them an email to make certain you should be getting NDS1 or 2 because they use different cables (the 4th gen is equipped with both connectors though. I'm just wondering if both programs are compatible with the ECM itself. or if both are compatible but only NDS2 has reprogramming options. I don't get why they wouldn't just list the A32 under NDS2 if it is compatible)

I have a 99 car but ECM and engine swapped it. so it has a 2003 computer and I use NDS2. Here's a link to the cable I purchased

Shrout1

Oooh I like how cheap that cable is... I will definitely shoot an email to the Nissan Data Scan guys before I buy.

If anyone else has connected to Consult on the 99, let me know what cable you use!

Shrout1

Dealer says that they can’t get consult to talk to the ECM. Ugh.

I told them to diagnose it but I’m feeling like this might be it... The wife might just leave me over this nonsense lol. Well... she’s gonna be pissed either way.

I don’t know if I can justify spending a whole rack of cash on this - I’m bound to be in about $400 by the time this diagnosis is done. I can only imagine what a used ECM will cost from a dealership.

Violator

I'm gonna ask you to check a CPL fuses before you pull your hair out. Fuses 57 and 58 under the hood (ECM power). They are 10A fuses I think labeled as eng cont1 and 2 or something like that on the fuse cover. Also look at the big green fusible links while you're in there because one of those is also used to power the ECM.

Also check fuses 13 and 40 under the dash(the plastic is labeled on these if you shine a light you'll see), these are power for the consult and OBD connectors.

Shrout1

This is also not hopeful:

Violator

Did you even read my previous post? Check those fuses before you pull your hair out. eBay and junkyards are better than buying one anywhere else for an arm and a leg. ECMs don't tend to "go out", take 2minutes check those fuses I mentioned and then we'll worry about finding an easy matching replacement for somewhere south of a $100. There are quite a few on eBay and they are easy to pull at a junkyard

Shrout1

Thanks for the encouragement! The dealer told me today that they checked the fuses, but I’ll probably have it towed back to the apartment and check it on my own.

I appreciate the help! Will keep you posted

Shrout1

Rockauto has different ECMs for the different transmissions. Do I need to get one that matches my car?

California emissions, manual trans. Rockauto is fresh out.

There’s a 99 at a junkyard in town but I doubt that it’s a manual.

Shrout1

Damn stealership. As suspected they screwed it up.

The tech put an OBD1 reader on it and didn’t troubleshoot the fuse correctly. They reprogrammed the keys and I’m outta here for $250... Something like $120 an hour for labor or some nonsense.

So I need to get Nissan Data Scan and the cable because there’s a bulletin out on my ECM and how it forgets the keys.

Sorry for all the drama. Going to get the alternator and battery tested too.

CS_AR

NDS1 will NOT reprogram keys on a 4th gen. It only works with NDS2 on 5th gens. Take that to the bank. Been there, done that.

Violator

That's unfortunate. I did once see a Nissan consult emulator on an automotive software forum. I'd have to go back and find it, and I'm not sure about the legality of posting it up here. I take it the OP is back up and running though

Shrout1

CS, are there any options for reprogramming it myself? Being beholden to the dealer does not make me happy, nor is it convenient when the car won't start :P Thanks for the heads up!

CS_AR

I haven't found an option. If you can run the actual Consult software, them possibly.

Shrout1

I got this response from the Nissan Data Scan guys:
I saw in another thread that there is a consult connector located in a fuse box in the passenger compartment? Under the dashboard on the driver's side? Supposedly the later 4th gens have 2 connectors. Poked around this morning but didn't see it immediately.

And then a later e-mail:

So it looks like you are indeed correct, NDSII doesn't work with the '99 and NDS1 doesn't support immobilizer reprogramming... Joy. I'm waiting to hear back from them with confirmation that the 99 immobilizer truly can't be reprogrammed.

Another question: Can I use the ECM from a later model Maxima in my 99? It looks like Violator swapped his out with a later one at some point.