Check battery and charging system.

 

Battery tests good, a bit high. 13.7v. Alternator tested good too. Not sure what else to check for the charging system. Learning as I go.

 

My 2015 Moran’s has been having issues lately. Occasionally, when I start to drive, the battery light comes on, and I lose acceleration. When this happens, there is a delay when I step on the gas. It will rev, but then stop even if I hold down the pedal. If I shut off the vehicle, disconnect/reconnect the battery, it will run fine for a while. I have been consistently seeing the codes -c1109 c1729 u0415. I’m not sure where to go, battery, ABS module, something else. Please help.

I have had (and still have) some electrical issues. What your describing sound like either battery, bad alternator connector, of ailing alternator. The first two are relatively easy fixes. Test your battery. You should see 13.8-14.4 volts. Locate the 4-pin connector and check for broken wires. It's a $14 part at local shop and fairly simple to replace. If it's the Alternator, you'll be in for a pretty hefty shop bill unless you're able to DIY. Good luck.


FYI, there are a ton of posts here on any of the above fixes. Use ChatGPT or other to help.

 

I have had (and still have) some electrical issues. What your describing sound like either battery, bad alternator connector, of ailing alternator. The first two are relatively easy fixes. Test your battery. You should see 13.8-14.4 volts. Locate the 4-pin connector and check for broken wires. It's a $14 part at local shop and fairly simple to replace. If it's the Alternator, you'll be in for a pretty hefty shop bill unless you're able to DIY. Good luck.


FYI, there are a ton of posts here on any of the above fixes. Use ChatGPT or other to help.

Got it — you’ve got a 2015 Murano that’s throwing codes C1109, C1729, and U0415, plus intermittent issues with the battery light, throttle response, and acceleration cut-out until you reset the system. Let’s break this down step by step.

🔎 Code Meanings (Nissan-specific)

• C1109 – Battery Voltage Low (seen by ABS control unit). Often points to alternator/charging system issues, weak battery, or poor ground.
• C1729 – Battery Voltage Abnormal (from the AWD control unit). Same story: charging system supply voltage problem.
• U0415 – Invalid Data Received from ABS Control Module. This is a communication fault on the CAN bus, usually caused by unstable power/voltage drops.

⚡ What’s Happening

• When your battery light comes on, the alternator may be dropping output (or voltage is unstable).
• The ECU, ABS, and throttle control modules all depend on stable 12–14V. A sudden dip (bad alternator, corroded connections, weak battery) makes the modules freak out, which explains:
  
  • Throttle lag/stall (the ECM can cut throttle when CAN signals go haywire).
  • ABS/traction codes (modules lose or reject data when voltage drops).
  • Temporary fix when disconnecting/reconnecting the battery (resets the modules, but root issue is still electrical).
• 
  
• 🛠 What to Check (in order)

1. Battery Health
   
   • Test resting voltage → should be ~12.6V.
   • Under load (headlights, blower on) → shouldn’t drop below ~12.2V.
   • Weak battery can trigger C1109/C1729.
2. 
   
3. Alternator Output
   
   • Engine running → voltage should be 13.8–14.4V.
   • If it drops out intermittently or spikes above 15V, alternator is suspect.
4. 
   
5. Grounds & Connections
   
   • Clean/tighten battery terminals, chassis ground strap, and alternator connections.
   • Corroded/loose grounds are common Murano gremlins.
6. 
   
7. Charging Circuit Load Test
   
   • Auto parts stores (Advance, O’Reilly, etc.) will do this free.
   • They can confirm if alternator is failing under load.
8. 🚨 Likely Root Cause

This is not the ABS module itself. The ABS/ECU are just the “victims” reporting the bad data.


Given your symptoms + codes, I’d bet on:

👉 Failing alternator or bad connection in charging system.
✅ Next Move:

• Get the battery and alternator load-tested.
• If alternator is weak/intermittent, replace it.
• Only chase ABS/communication faults after confirming the charging system is rock-solid.

 

I would bet this ends up being a flaky alternator as well. The worst part about trying to confirm it's the alternator is that they can drop out of regulation intermittently and then act normal later. The charging voltage can look fine when you check in your driveway for 5s with a meter or take it to a parts store or even the dealer to have it checked. So many threads here where shops have a difficult time identifying alternators that are dropping out intermittently because they don't monitor them long enough to experience the problem. The best way to be sure if your charging system is dropping out of regulation and causing the problem is to monitor it while you're driving. If the drivability problem pops up and you see the voltage is low (or really high), you'll know for sure it's related to your alternator output. There are cheap obd interfaces that work with free apps for your phone or almost any basic scanner can monitor the battery voltage while driving. If your battery light is being lit up on your dash even intermittently, that's your alternator telling you something's wrong. You're lucky because my 2nd gen oem alternator crapped out and never lit that light. Just stopped charging until the car died and stranded me.

Also 3rd gens have electric power steering and there are a number of threads here where the poor throttle response comes on specifically after initiating a turn. There's a good youtube video with a 3rd gen repair like this.

Good luck and let us know how it turns out.

 

My mechanic has not been able to replicate the issue, nor find anything causing the problem. Per his discussions with other mechanics, he thinks it may be the crankshaft sensor. He did note the battery looks a bit swollen, so I will replace it. Fingers crossed the battery magically solves everything.

 

You both need to monitor the charging voltage while you're driving (not parked in the driveway or parts store parking lot) and look for unexpected excursions high or low from the expected charging range when the problem occurs. There are cheap tools that enable you to do this like voltmeters that plug into your cigarette lighter or $10 obd interfaces that enable you to log data on your phone. If you observe it going out of regulation, that will confirm you have a charging system problem. This is the most likely scenario based on the many many threads here but you won't know for sure unless you capture data to confirm it. If the problem doesn't pop up in however long the shop was observing the car, they're not going to find it. You need to do the observation if you want to be certain. If the car stops responding to your throttle input and you don't observe strange charging voltage, at least you know it ISN'T the charging system and then you can look for something else.

And @Genofett, if you have a crank sensor going bad it will stutter like you're hitting a rev limiter and then recover to completely normal driving not like a limp mode. It'll go good and bad intermittently more and more often probably until it eventually dies on you while driving and won't refire and THEN it will set a crank sensor code. I had that. What you describe, doesn't sound like crank sensor to me at all. It sounds like a **** alternator which I also had.

Good luck to both of you. Hope you find it before you get stranded like me.

 

Man I’m hoping it’s not the alternator. My mechanic has been diagnosing while driving, and said he hasn’t found anything out of the ordinary. I’m heading to get a battery right now, so we’ll see how things feel after.
thanks everyone that’s replied so far I appreciate it!

update: replaced the battery, and I only have one code left.C1729. I fairly recently replaced a loose stud on my front driver side wheel. Could the loose stud have caused an issue with the vehicle speed sensor?

 

It's possible.... but i would have thought you would have heard it when you were driving if it was bad enough to throw a fault code ?. Mind you,,,on the older Murano,, if you have uneven tyre pressures , it can cause a fault code that comes and goes, but we're talking quite a few pounds between front and back pairs.

 

In my case I changed the alternator and now everything is ok So anybody who got same issue must change the alternator thanks