Hello,

Kind of new to this forum, found it while searching the web for some ECU information. I've been reading up in other forums and see that there are quite a few knowledgable regulars on this board and would like to solicit their suggestions.

I am working on a projet to hack into the ECU of a 1998/99 maxima ECU's. My car is a 1998 so that is what I will be using to test.

The goals of this project: 1) Modify the Rev Limiter 2) Modify the A/F mixture.

Any help that you guys can provide would be greatly appreciated.

Thank you,

Jasmeet

Thank you very much for the link. I'm not on the org that much any more, but that is one hell of an informative thread. The 98fivespeed guy will ABSOLUTELY have to have a Nissan consult to do this though, and that is $$$$.

My best advice is to buy a '95 or a '96. Sorry.

What about the freeware consult? Its been used by SR20 and 300zx tuners for a while now I believe. Even a commercial version is available, conZult?

And that 98fiveSpeed guy is, as you can see, me. I have the freeware version of the consult interface built. I am hoping to test asap.

Do you have any other information on the Nissan Consult interface that you speak of? and how much is $$$$?

Thanks again!

-Jasmeet

LOL

I just realized who you were. Welcome to NICO.

NISTECH, could probably help you with more info on the consult.

what is it you want to know about it. I did not read the thread I dont venture out into other forums much. I like it here...lol

And we like you staying here too

I did read the thread and its pretty interesting, but way over my head. Just not something I want to learn (plus I have an '02 anyway). In a nutshell, they are trying to crack the ECU using a OBDII reader to dump the information. They determining the manufacturers of the IC's and such as well. Looks at this point that changes to that ECU can't be stored permanently, but they are working on it.

Hopefully jasmeet will post again here as this may be viable information for the Nissan community as a whole.

I do know those ecms are not flashable,meaning consult can not reprogram them. That started in 2000 that the ecms were made reprogramable. I do know after market places do do things to the ecm which they call tuning. But what I think they do is add hardware piggy backing chips inside,likely the processor, so when the key is cycled it does not revert to base values. I dont read up on those tunning things much as they ,at this pont in time, dont really intrest me.

I will update this thread as well as I wouldnt want to direct any traffic from here.

NISTECH wrote:I do know those ecms are not flashable,meaning consult can not reprogram them. That started in 2000 that the ecms were made reprogramable. I do know after market places do do things to the ecm which they call tuning. But what I think they do is add hardware piggy backing chips inside,likely the processor, so when the key is cycled it does not revert to base values. I dont read up on those tunning things much as they ,at this pont in time, dont really intrest me.

So far I have come to know the following:

1) Some? ECU's can be reprogrammed via the OBD-II port. But all writes via the OBD-II port must be encrypted. This would not be easy

2) Nissan's appear to use the Consult port for interacting with the ECU. The protocol has been analyzed and a command set has been reverse engineered by some folks and is available here: +http://www.users.bigpond.com/webspace/plms/ We can use this and develop further and see what we can do..

3) As documented in the Consult_Protocol_&_Commands_Issue_6.pdf, avaialble at the above url, we can temporarily alter the ECU outputs of fuel and ignitor timing. I guess this is where the piggy-back systems come on? Are these systems, that you speak of, doing this via the OBD-II port? or the Consult port? Or something else? I am very interested in this and would love to hear some more information.

I have built my consult interface, but the car has a bad alternator. I am going to work on the car asap and see if my circuit works. I will keep you guys posted.

-Jasmeet

4. Activation Commands – To alter ECU output4.1.1. Commands to temporarily alter ECU outputs for Fuel, Ignition timing andrelays etc can be done by sending a Activation byte (0x0A) then a activationtype register to set followed by the new register data. Registers and resultsare in the table below. Eg 0x0A XX YY where XX is the test type, YY is thedata. Terminate the command with F0.

I take it you have never really used an actual consult unit? To answer your question about the 2 ports. The obdII port is not used by nissan. that port is simply a data stream for generic scan tools. You can not do anything with the ecm through that connector except read info.

The consult connector is what nissan uses to communicate with the ecm and send requests to have actuators perform a task. There is only one or 2 things you can semi perminantly set. one is target idle and the other is timing I believe.

What it sounds like you are seeing or screwing with is a function of the consult called function test and/or active test These particular functions allow you to adjust fuel injection up to 25% above and below the current alpha. Adjust timing up or down I think its 10 degrees, Adjust your idle air control valve through its full travel to change the amount of air its taking in. and a few other things. But when you exit that mode in consult it reverts to what it was or exits the test mode it was in. If you are doing this by other means it may just not be exiting the test stage untill the key is shut off which is what the consult does when the key is cycled. It exits what ever setting you had it at before you shut the key off and starts over once the key is turned back on.