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2009 Murano, 80k miles; Dead Battery after Alternator & Battery replacement

2423 Views 48 Replies 4 Participants Last post by  VStar650CL
So, as the title says, I recently replaced the alternator and battery after losing power while driving and nearly not making it home. I took the alternator off, with much difficulty, and took it to be tested to confirm that it was at least part of the problem. The auto parts store said that the alternator did need to be replaced. I purchased a new, not rebuilt, alternator from RockAuto (Pure Energy brand, manufactured by Mitsubishi) and put it on a couple weeks ago. Even after charging the battery that was in the vehicle at the time I was not able to get it started. Fortuitously, the battery was just inside the replacement window and I was able to get a new one at no additional cost. They didn't test it or anything but I took the new one home, put it in, and it started right up. So I figured it was fixed. It ran fine for a couple of weeks until yesterday when I went to start it and all I heard was the starter clicking. I had to be somewhere so I just took a different vehicle. When I returned, I tried again to start it even though I knew it wouldn't, and the starter clicked again, and then there was an audible clicking inside the vehicle that would not stop until I disconnected the battery. I'm not sure if that's a symptom of anything as "newer" cars with this electrical wizardry, and this car in particular, seem to do strange things when something isn't right with the electrical system. As a side note, when I was first trying to confirm if the alternator was indeed the culprit, similar to the nonstop clicking inside, the lights came on and stayed on (albeit dimly) until I disconnected the battery.

Long story short, I replaced the alternator and battery with new ones, ~2 weeks later the battery appears dead and the vehicle will not start. Any ideas as to what could be killing the battery? I really don't look forward to pulling the alternator out again to have it tested and I'm not even sure if they can test to see if it's draining the battery when the car is off.

Any input is greatly appreciated because this is quite frustrating to say the least.

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Can't catch a break. Put the new one in and the parasitic drain is gone, but when I went to put the main lead from the battery onto the alternator the charging post pulled basically all the way out. It wasn't flopping around before I put it in, or at least I didn't notice it but it's floating around really bad. I assume it would pull all the way out if there wasn't so much stuff crammed around it to prevent it from doing so. I figured I'd give it a shot since I had it basically all the way in and of course there's some variable idling going on and it sounds like it wants to die on occasion. I presume this would be indicative of a bad connection to the battery and not something to do with the alternator plug? I replaced that as well while I was in there because as a result of all of this fooling around with it the plastic just started to break apart.

I'm sure the post got damaged in transit because it kind of sticks out and there's not a lot to prevent it from taking the impact when getting thrown around by the carriers and I guess the pressure of the wire was enough to set it free.
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Pot metal. It's a wonder it ran at all.


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From the dimple at the base of that break, I'd say the casting already had a fatigue crack in past life. Somebody in QC missed it.
I put the third new alternator in and there's still problems. The issue is similar to what it was doing when the one with the totally broken charging post was installed - RPM dropping down during idle to around 500 RPM and sounding like it's going to die although it isn't as bad as the previous one, presumably due to the totally detached post. When I was screwing down the wire on the current one I noticed that the post would rotate ~15 degrees or so forward and backward as you're facing the front of the vehicle. I don't know if this is supposed to be a 'feature' of this particular alternator (I purchased a different brand this time and it seems like the post is a solid piece of steel unlike the previous one which was cast. The alternator that originally failed on me seems to have a similar post but it doesn't move at all.) Before I put it in I thought I carefully examined the charging post for any issues, although I suppose I was more focused on if it would pull out like the other broken one.

I also replaced the alternator plug since with all of the action it's been seeing the brittle plastic basically fell apart. So now my question is would this idle issue be more likely to be related to the plug and or one or more bad plug wires or to the charging post situation? The new plug was in place with the previous alternator with the broken post so it could be either one or both I suppose. Are these things really that fragile that installing it and putting a stiff wire on it would cause the post to break loose and not perform correctly? It's just crazy.

Anyone want to buy a Murano?
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Chances are your idle issue is unrelated to the alternator. Low voltage can cause a lot of problems but idle or surging issues aren't usually among them. Check the alternator output, if it's around 14V at normal idle speeds then it isn't causing your problem and you need to bark up a different tree. Vacuum leaks at the Throttle Body were a common issue on gen1 and gen2 Muranos due to the short lip on the inlet side of the TB.
There seems to be myriad issues at this point. I was measuring the alternator output and it does seem to stay above 14 volts, if anything it seems to slowly drop down by millivolts and then back up a few, then back down a few more. Minor issue at this point as the check engine light came on while I was doing this and has stayed on. I went to a local auto parts store to see what their limited equipment would be able to tell me knowing that it wouldn't be much other than general information. There were 10 codes thrown by this thing including:

B1018 - OWD Error Info DATA5
C1109 - Battery Voltage Abnormal
P0725 - Engine Speed Sensor Circuit Malfunction - microcuts
U1000 - CAN Communication System - no signal
P1722 - Vehicle Speed Signal Error - microcuts
P1701 - Backup Error - microcuts
P0300 - Random - Multiple Misfire Detected - open circuit
P0171 - Bank 1 System Too Lean

There were some duplicates of the above error codes.

As previously stated, the abnormal idle condition first presented when the second alternator with the bad post was installed, but the check engine light business is new. Admittedly, I didn't run it all that long with that particular alternator.

I don't know if this helps at all but the idling down seems to occur in a pattern. I.e. ~26 seconds of normal idle followed by ~4 seconds of idling down. This pattern repeats. During the idling down cycle there is a clicking or popping that can be heard from near the alternator. I've provided a video link in an attempt to illustrate this. There is a lot of noise but the clicks can be heard at
21 seconds and 51 seconds.

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The lit MIL is from the P0300 and P0171. Chances are the repairs created a vacuum leak someplace, maybe in the active motor mounts. The older Muranos also have a very thin lip on the throttle body which can allow the boot to slip off when the engine is tilted for repairs, that's a very common issue.

The P0725 and P1722 are related, they both mean the ABS quit sending vehicle speed signals to the tranny. They're usually caused by a bad wheel sensor causing the ABS to go offline, but in this case I'd be pretty sure they resulted from the car being operated with low voltage. The rest of the codes are pretty clearly just trash from a dead battery that went into "never never land" below 9V.
Regarding the throttle body issue, would this be something that's evident when looking at it after disassembling the airbox, etc.? Should the gasket be replaced while it's all apart?
When the rubber boot slips off it's always where it meets the throttle body, so if that's the issue then there's no need to take the TB loose. Just get the boot back on the lip where it belongs and tighten the clamp. But on an '09 it's just as likely the boot has hardened and cracked, you should inspect it carefully. If you do need to take the TB loose, a new o-ring is generally needed only if the old one comes unseated. If it stays in place, re-use it and just make sure the mating surfaces stay clean.
It looks like the boot is where it's supposed to be. I don't see any cracks, although I can't really tell underneath. Otherwise the boot seems to be in relatively good shape and doesn't seem brittle.


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It would really help if you had your own scanner, consider getting a $20 Bluetooth-OBD dongle and downloading a $5 copy of Torque Pro onto your phone. That will let you stream most of the things which can cause a P0171 and easily diagnose whether the issue is a vacuum leak or something else. Since this happened immediately following a repair, I have to think it's related, and a cracked or misplaced vacuum hose would be the first place to look
Do you have a recommendation for a dongle?

After a quick look this one seems to have good reviews for the most part and specifically recommends Torque Pro. I'm open to other suggestions though.

I use the Veepeak VP11 because it's also compatible with the CVTz50 app for looking at your tranny. CVTz50 is fussier than Torque and NDS-III about what dongle you use, the VP11 is the cheapest one that works with all of them.
Any known drawback to getting the veepeak obdcheck ble plus?

I can't really see a difference except for more apps advertised as being compatible.
I dunno. It probably doesn't matter if you don't care about using CVTz50, but CVTz50 is the only app I know about that can monitor your tranny. Torque and NDS-III aren't CVT-capable, they'll give you codes from the TCM but that's all..
Torque returns two error codes: the p0300 and p0171. Pictures are attached. There's not really any more information available unless I'm missing something. The web lookup option leads to the following web sites:


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The P0171 happens when the ECM hits a maximum +25% enrichment and can't go any further, but it shows as "pending" which means it happened once and the ECM hasn't seen it a second time. P0171 is a "two-trip" code which only lights the MIL after two consecutive instances. So the condition isn't chronic or it would show as "current". The P0300 is what we need to track down, but there are a lot of things which can cause that. Stream the STFT, LTFT, and O2 sensors for both banks, at idle speed and again at 2K RPM with the engine warm. That should help discriminate whether the misfires are from induction or spark and suggest what trees to bark up first.
Where do I find the appropriate PIDs for STFT and LTFT? There aren't any predefined sets for Nissan that I'm seeing, only Chrysler/Dodge/Jeep/Mercedes, so on and so forth.

Searching for plugins on the store yields no results. I found something called Advanced EX for Nissan searching elsewhere but I can't use it because it was made for an older version of android.
Those are OBD parameters, they're not Nissan-specific. If Torque isn't doing it for you (I don't know why), try NDS-III. That's a Nissan-specific app.
I found a way to monitor the appropriate PIDs for STFT, LTFT, and 02 sensors. However I'm not seeing a good way to capture and export that data in a meaningful way. I thought I had figured it out by setting up the real time information tab in Torque pro with gauges for the aforementioned data and capturing the log within the menu for that part of the application. However when I looked at the logs there's no useful information there, only columns with device time, x, y, z, and calibration axes.

Other than this I can provide screen shots of graphs, but that only represents a snapshot in time obviously. Or perhaps a screenshot of the screen with the STFT, LTFT, and 02 Sensor gauges at idle and at 2000 rpm. Would this be useful?

Something I did notice is when it idles down stft1 and stft2 drop from 25 to 0. This also seems to occur at 2000 rpm in the same intervals although it's not obvious that it's happening outside of the gauges dropping in torque pro.
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