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Computer stopped working 1998 Nissan

My 1998 Nissan Altima 4 cyl (auto) shut down on highway, would not restart, and had to be towed. My mechanic told me it is the computer, which will cost me $1,000 to replace with labor. After seeing prices for new ECMs from a Nissan parts site for less than $550.00, I am wondering if something else needs to be replaced. I don’t want to put that kind of money into a 14 year old car with other problems and mileage of 155,000. Could whatever caused the computer to stop working be an additional cost. The mechanic provided minimal information and is actually recommending I get rid of the car due to a slow oil leak and control arm bushings that eventually need to be replaced. However, it just passed inspection and a few months ago, I replaced 4 tires and brake rotors.

None of US have enough information to even give you an educated guess…If there is no SPARK, then the ignition module becomes suspect…We just don’t know the diagnostic capability of your mechanic…Does he KNOW it’s a failed ECM or is he just guessing and figures he can cover all the bases for $1000…

Perhaps a Nissan dealer is your best bet in this case…

He said there is a spark and fuel. I don’t believe he is guessing doubt his diagnostic ability but think he’s a bit overpriced or maybe not telling me everything, like what caused this to happen in the first place with no warning whatsoever.

Thanks for the suggestion, but I really don’t want to be towing this all over just to hear the same thing at the same cost.

It could be that the driver for the fuel pump relay in the computer has failed. This would cause the engine to shut down and not restart or run. How do I know this? The driver for the fuel pump relay in the computer failed on my 95 Nissan. So right now I have a jumper wire in the fuel pump relay socket so the fuel pump runs without the computer. But it runs all the time when the ignition switch is on.

Try calling local auto recyclers to see if any have a used computers for your vehicle. Then find a shop that’s willing to install the used computer. That’ll be a lot cheaper.

Now if I could only find a used computer for my 95 Nissan.


“He said there is a spark and fuel.”…Has he checked the timing belt / chain??

Here we go again. Some codes you get with an OBD II tester can indicate a failed computer. If the tester can’t communicate with the computer, it may be wiring or bad computer. Unless you get the results, you’ll never know if the mechanic is pulling info from his nose. Some computers can only be installed by the dealer because only they can program the thing. A used one might work without programming but it could be bad too. It could be best to replace the car but somebody can fix it.

There’s not nearly enough info known so as to make a guess about the problem. Shutting down quickly on the highway could be due to any one of a number of things.
Even the part about having fuel could be iffy. There can be fuel present in the fuel rail but that doesn’t mean there’s enough fuel or pressure to allow the engine to run.

Assuming there’s no problem with the valve train and IF the spark is good and IF the fuel pressure is correct then the next thing I would want to know would be if the fuel injectors are pulsing while the engine is being cranked over.
Inoperative fuel injectors or even the computer could be due to a faulty fuse or something simple.

I spoke to my mechanic again. He said it is the computer, not the ECM (I thought they were same?) and that he cannot get a used one. The part is about $725 and another $125 to reprogram it. He cannot tell what caused it because the scanner cannot read any codes from a nonworking computer. I’m really in the dark here about this whole topic, as you probably can tell.

ECM stands for “engine [or electronic] control module” - same thing as an ECU where the “U” is unit.

Another thing you’ll see is “PCM” which is “powertrain control module.”

Either way - its the “computer.” The thing is that many vehicles have multiple “control modules.” Others don’t. I don’t know about your Altima. What I do know is that I’m now a bit suspicious of the mechanic. If the car stopped running due to a bad “computer” I can’t imagine how that could be anything but the ECM, even if its not the only control unit. Did s/he happen to say anything about a “BCM”? (body control module)

Perhaps a 2nd opinion is in order, though I know that’s complicated when the car won’t run.

I sympathize with your plight. Once after completing a bunch of repairs I pulled in my driveway just from the tire shop with new set of tires only to have the timing chain break. The car was 18 years old and had 200+K hard miles. It was a killer to see those new tires carried off to the junkyard on a flatbed, but it was time to let the car go.

The ECM or “computer” (yes they are the same) like any other electronic device can fail suddenly with no outside cause. A failed ECM in a 14 year old car isn’t unheard of. Considering the other things you know the car will need, investing in the ECM is a big gamble. A $1000 seems a bit high. For that I would hope the mechanic is buying the ECM from the dealer. Even if you could have the car towed somewhere and get the ECM replaced for $600 you still need to spend money on the problems you already know about and probably a bunch of others that haven’t shown up yet. The big unknown here is your mechanic. He could be acting prudently on your behalf or not. There isn’t enough information to guess one way or the other. Either way you have an old car that is going to need a lot of work. I know it’s hard to walk away from the tires and brakes but I think it might be time to cut your losses.

I suspect there may be a power problem that is causing the ECU to not work. Hopefully the tech checked that out first before saying the ECU was bad. Here is a link for some rebuilt units that cost around 300 dollars if you really need one.

I would hope that the failure is correctly diagnosed and that it’s not something as simple as a bad fuse, wire connection, ignition switch, etc.; as in not having the destop PC plugged into the wall or a bad circuit breaker situation. Hopefully, any power sources have been verified and known to be good.