Can anyone help. I have a 2009 Nissan Rogue that is throwing a P0603 Keep Alive Memory error code. It is intermittent and comes off and on at various times. It has a brand new battery and the Rogue is running just fine with no issues other then the error code and check engine light.

Check your battery connections, P0603 is simply a low voltage condition at the ECM while the car isn't running. If not a bad battery, it's almost always caused by corroded battery connections. There's a bulletin about it:
http://www.370zcoupe.com/TSB/1SE8.pdf

Frequently the voltage loss will occur with the car off during EONV testing of the fuel tank, while the ECM is drawing current to run the vent solenoid and purge hardware. So the light will usually pop on after the car has been parked. If it keeps recurring and you can't find a cause in the battery connections or grounds, you'll need to take the backshell off the ECM "E" connector and check voltage and pin-fit at the power and ground terminals.

Thank you so much for the quick reply vstar650cl! Could a failing alternator cause this issue also? However the new battery has been in the car for over two weeks with no issues of draining.

The power still needs to reach the ECM. That means a trip on the "E" harness through the fuse card on the battery to the IPDM, through fuse 62 and out of the IPDM on pin 61, through wire-to-wire connectors E8:F122 pin 2 into the "F" harness, and finally to ECM pin 77. A problem with any portion of that could cause P0603 or P0605.

Thank you very much for the detailed information. Much appreciated and valued.

So I took my Rogue to the local Nissan dealership and they said the pcm was bad and that the service bulletin did not apply to my Rogue which I thought was odd. They wanted 2,500 to replace the pcm. I declined and am ordering a pcm through flagship one and going to replace it myself.

It's an ECM, there's no "PCM" on a Nissan. It also isn't plug-and-play, at a minimum you'll need to have the keys programmed. Most mobile smithies can do that for you on an '09. To do it right, you should also perform IAVL (idle Air Volume Learn), CTPL (Closed Throttle Position Learn), and then program your VIN number into it. Good scanners have work support for all of that. Most importantly, make sure the Hitachi p/n on the outside of the new one exactly matches your old one. If it doesn't, you'll end up chasing your tail. For an '09 Rogue, it will be MECnnn-nnn where the n's are numbers. It must be an exact match.

Thanks for the heads up on the reprogramming. The flagship one had me input the VIN number so I was assuming it would already be programmed and ready to go. Does that sound right or will I for sure have more programming to do?

They were probably just matching the ECM to your specific vehicle to make sure you got the right one, which is good. Whether they actually program it into the new unit, you need to check with them. It will still need the other stuff, key programming, then IAVL and CTPL. Those are mating the ECM to your BCM, IMMU, MAF and TPS, so they can't pre-do them for you.

Thanks again for the awesome reply. You have been a great help for me in my situation. Where exactly is the ECM located for my 09 Rogue? I have searched around and I think it’s under or behind the battery compartment.

You're most welcome. The ECM is directly in front of the battery, with 3 connectors. The TCM looks similar and is directly behind the battery with 1 connector. See page EC-509, it shows where everything engine-related is located:
https://www.nicoclub.com/service-manual ... 9%2FEC.pdf

PS - Disconnect battery negative before starting work and don't butch the ECM connectors. On an older ride I strongly recommend dousing them with WD-40 or PB Blaster before removal, to flush out some of the crud and make sure the latch arm is free. There's a pic in this post that shows how to release them:
post6828239.html

Thank you again that ECM is in an easy spot for removal. Thanks for telling me about disconnecting the negative terminal also. I’ll make sure to douse those connectors before I remove them. I guess I need to be careful not to get any wd40 in the connectors though. Hopefully the part will be here in about a week and I’ll switch the PCM out. Thanks again for your help as this is saving me a lot of money. I already had to spend a little over $700 to get the clock spring installed because I was nervous about messing with the airbag module.

jeff112405 wrote: ↑

Thu Mar 10, 2022 6:47 pm

Thank you again that ECM is in an easy spot for removal. Thanks for telling me about disconnecting the negative terminal also. I’ll make sure to douse those connectors before I remove them. I guess I need to be careful not to get any wd40 in the connectors though. Hopefully the part will be here in about a week and I’ll switch the PCM out. Thanks again for your help as this is saving me a lot of money. I already had to spend a little over $700 to get the clock spring installed because I was nervous about messing with the airbag module.

Disconnecting the negative goes for replacing any piece of electronics that has a battery connection. For devices that only have an Ignition supply you can leave the key off, but anything with a battery supply can be harmed by "hot plugging". You remove the negative because any sparks on the ground side will be weak and depleted. Sparks at the hot terminal are much stronger and can be damaging. Not to mention, you don't want to short a wrench on the hot terminal while the negative is still connected -- arc-welded wrenches won't be pretty anymore, and sometimes neither will be the hand that holds them.


No worries about WD inside the terminals. It has a very high dielectric and is actually healthy because it chases moisture. Obviously don't fill the cavity with it, but a film is completely harmless.

Wanted to give an update. The company I ordered the pcm from said the pcm would be plug and play and they were right. I did not have to program anything and so far the check engine light has not come back on. I appreciate all your advice for my issue as you were a tremendous help! Thank you again.