Battery Corrision/ computer fry


I am being told by the Nissan dealership that my battery had corrosion and that it caused the computer to fry. They are also telling me that the computer will not be covered under warranty because it is my fault for poor maintenance. I choose not to go to this dealership for anything because of poor service and baqsically being given the “run around”. I’ve been told by my father, who is a retired mechanic of 50 years" and several other mechanics that the battery has nothing to do with the computer. Can you tell me what you think of this situation???>

I go with your father. What year/model/miles Nissan?

I wouldn’t say that a battery has nothing to do with the computer. Obviously it does since that’s where the computer gets it power from.

What maintenance are they saying you missed?? Nissan hasn’t sold a battery that requires maintenance in years.

Counter point:

Yes, if the connection to the battery is lost while the engine is running, the PCM can be damaged by the AC ripple and voltage spikes coming out of the alternator without the battery there to filter it out.

My father once thought that he had an alternator problem on his Crown Vic (he didn’t). He started it and then disconnected the negative battery cable briefly to see if it would keep running. Smoke came out of the dash and a couple of electronic modules were destroyed. The alternator was fine.

Go to a different nissan dealer.

Surface corrosion on the battery terminals is not a reason to deny warranty service for a car.
Take that one up the Nissan hierarchy, and I bet you get a better resolution.


I think there are some issues with the Nissan ECUs depending upon the year. You might try doing a web search on that.

They are also telling me that the computer will not be covered under warranty because it is my fault for poor maintenance. Have them show you where in the owner’s manual it tells you to clean the battery terminals.

Nissan pathfinder 2008 with 35,000 miles. I bought it in 2009. They are also being quick to try and sell me a new car.

I am being told that the reason is poor maintenance since I took it elsewhere to get serviced. I choose not to deal with this dealership because of their poor service. Now I am really sold on the “poor” service. They are also telling me that it isn’t up to them, but to Nissan in gerneral. The general manager also mentioned how they recently had 4 to 5 other cases exactly like mine that were denied the “Good Will” policy. Hmmmmm…4 to 5 cases exactly like mine…and recently? Sounds fishy to me.

I’m in agreement with Mr. Meehan and I think you’re being yanked around a bit by a clueless service writer or service manager.

Since the computer is under a Federal Emisssions warranty for 8 years/80k miles maybe you should let the dealer know you will file a complaint with the Feds and mention the service writer or service manager’s name while doing so.

Now that we have more information.

They can NOT deny your claim. Go to another dealer…or go up the chain. It’s spelled out in your owners manual what steps to take.

Here is a TSB from Nissan about battery connections and note it says that a ECU will not be covered.

Classification: EL09-011

Reference: NTB09-030

Date: April 6, 2009


All Nissan


^ The vehicle 12 volt battery is an important part of the vehicle electrical system and is required to stay connected when the engine is running.

^ To prevent damage to vehicle electronic components follow the instructions / cautions below.

Damage to electronic components (ECM, TCM, BCM, etc.) due to improper battery connection will not be covered under warranty.

CAUTION: ^ Make sure the ignition is OFF during battery service and replacement.

^ Do not disconnect or connect any battery cables while the ignition switch is turned ON.

^ When disconnecting a battery, always disconnect the negative cable first.

^ When connecting a battery, always connect the positive cable first.

^ Do not leave a battery cable loose. Tighten battery cables immediately after attachment.

^ If a battery cable is loose, do not operate any electrical loads. (This includes turning the ignition ON, starting the engine, operating accessories such as the A/C system, power seats, interior lights, exterior lights etc.).

^ When “jump starting” or “boosting” a battery - be careful. Don’t accidentally reverse the polarity of the cables.


Do you deny that your battery had corrosion? I conclude the Dealer is claiming that a less than nominal connection quality existed at the battery cable to battery area in your car. You can still file for warranty consideration (and make the Dealer prove that both the condition they claim existed,and that it was the cause of your ECU failure. I don’t know how they are going to do this.

GM had a tremendous amount of trouble with acid leakage from their Delco batterys (at the postive terminal from about 1995-2002). I corrected the effects of this acid leakage many,many time but I never replaced (an never needed to replace) and ECU over this corrosion. I think Nissan is working with a bad batch of ECU’s and is trying to make the customer bear the cost of replacing them.

File your claim for ECU replacement and see if you get anywhere with the agency in charge of processing claims for the 8yr 80K mile warranty (I believe it will be the EPA since the reason behind the 8yr 80K warranty is emission related). A denial by Nissan is not the final word on this issue.

That’s all nice and fine, but if the corrosion is just on the surface, and the connection between the wire terminals and the battery are perfectly tight, and there is no issue with the actual battery being weak, then that CAN NOT BE THE CAUSE FOR THE DEATH OF THE ECU.

The TSB clearly states loose battery connections, and the sequence of removing the cables from the battery. If the battery has never been replaced, nor the car never been jump started, then that is a NON ISSUE, and the TSB doesn’t apply.

In fact, the TSB mentions NOTHING ABOUT CORROSION.

The dealer has nothing to stand on.
They are obviously, one of the fabled bad Nissan dealers.

Labandnerd, take your car to another Nissan Dealer.
Yours sucks.


What’s the name of this “wonderful” Nissan dealer?
Maybe other people on here will know to steer clear of them in the future.

Go find yourself another dealer, as this one isn’t interested in having you as a customer.


I’m not saying it was right for the dealer to decline the repair based on this TSB, but this TSB is probably what they are basing their claim on. I assume they are saying the poor connection is based on corrosion.

A corroded connection is a improper connection but who is responsible is up for debate in my opinion. It is not mentioned in the owners manual but who is ultimately responsible for maintaining their car, the owner.

Translation: the electronic modules were poorly designed. A ten or twenty cent capacitor from the supply line to ground would have completely prevented that failure. Automotive engineering at its finest…

Just saying.

Do you really mean that corrosion is considered “improper battery connection”?

What would you call it. Corrosion on a connection makes it a poor connection. Corrosion causes voltage drops and that causes problems with the electronics in the car.

I fully agree. I design electronics for a living, and it doesn’t cost much more at all to make them immune to such surges.