# 2014 Rogue S - Charge Warning Lamp



## anjp (Jul 3, 2016)

Finally traded away my 2006 Nissan X-Trail for a 2014 Nissan Rogue S with about 74,000 kms. Unfortunately the Charge Warning Lamp comes on at start and remains on no matter what. Have already tested generator voltage (around 14 V), and previous owner says they swapped battery and generator in an effort to diagnose. There are no other apparent symptoms... I just drove 2,000 km without any incident, charge light on the whole time.

Service Manual "CHG" says the charge warning lamp comes on if either Excessive Voltage is produced or No Voltage is produced. Obviously voltage is being produced so I think it's a false positive. Any ideas? I'm thinking my next move might be to replace the battery current sensor which is apparently attached to the negative battery terminal.

Thanks!
anjp


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## rogoman (Dec 16, 2004)

Is the "charge warning light" on only at idle or is it on at higher RPMs? The voltage at the battery should be between 13 - 16 V with the engine running. Make sure there is proper belt tension. Check the voltage between the positive (+) post of the battery and the "B" terminal on the alternator; it should be no more then 0.2 V with the engine running; the wire color code is B/R.


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## anjp (Jul 3, 2016)

rogoman said:


> Is the "charge warning light" on only at idle or is it on at higher RPMs? The voltage at the battery should be between 13 - 16 V with the engine running. Make sure there is proper belt tension. Check the voltage between the positive (+) post of the battery and the "B" terminal on the alternator; it should be no more then 0.2 V with the engine running; the wire color code is B/R.


It's always on, no matter the RPMs. I took it to a Nissan dealer today and they couldn't figure out anything after an hour of investigation. Alternator tested good. Battery tested good. There are also apparently some communication codes present that do not produce a check engine light: U1040, U1044, U1051. 

Service desk ultimately had no idea and said they could just start replacing alternator, ECU, wiring harness at random....

A friend thinks it could be this module on the battery post that apparently has something to do with voltage regulation (picture). Does anyone know the name of the part?


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## rogoman (Dec 16, 2004)

That unit is the primary fusible link box. There are two other fusible link boxes that feed off the primary box. If you plan to trouble-shoot the problem, I would suggest that you get a copy of the FSM for your vehicle. You can download a copy of the FSM from this web site: Owner's Manuals. The ELECTRICAL & POWER CONTROL section contains PDFs that will help you.
.


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## anjp (Jul 3, 2016)

Thanks. I do have the OM and FSM and have been reading the applicable sections. Is it possible thecharge warning lamp is on because there's no Battery Current Sensor? 

The OM 8-15 (below) references a current sensor as part of the variable voltage control system (it does not appear in in the FSM CHG-6 diagram). As you can see in the under-the-hood photo, the negative terminal wire is fastened directly to the negative battery terminal post (purple). The fusible link is there (yellow), so is the Electronic Control Module - ECM (green). But no current sensor.

In reading here: 2016 February-March Issue 6 TechTalk Issue it looks like the current sensor is an integral part of the variable voltage control system, and the lack of it might trip a charge fault.


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## Punasan (12 mo ago)

anjp said:


> Thanks. I do have the OM and FSM and have been reading the applicable sections. Is it possible thecharge warning lamp is on because there's no Battery Current Sensor?
> 
> The OM 8-15 (below) references a current sensor as part of the variable voltage control system (it does not appear in in the FSM CHG-6 diagram). As you can see in the under-the-hood photo, the negative terminal wire is fastened directly to the negative battery terminal post (purple). The fusible link is there (yellow), so is the Electronic Control Module - ECM (green). But no current sensor.
> 
> ...


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## Punasan (12 mo ago)

I have 2017 Nissan Rogue Sport (26K miles) and Battery warning light first appeared on Jan 1. Battery tests and alternator under no-load and load test showed ok, the OEM EFB battery about 5 years old was low on CCA and being in Northeast and winter here, changed to Interstate AGM battery of same H5 (47) group as Nissan batteries are back ordered in my local area.
Also since Nissan has not published specs of the OEM which is discontinued and replacement battery other than H5 in part number, it was a struggle to find replacement as most battery finder sites/database say no aftermarket battery available for this vehicle.
However, coming back to issue, I still have battery warning light and i have driven about 10 driving cycles and around 80 miles and hoping that by 100 miles ECM relearns and the warning sign goes away. Only recent (or CRNT=current) DTC codes are U1040 (faulty ECM or faulty communication) U1044 and U1051. And just like in your case Dealer wanted to replace Alternator and I asked him what assurance can he say that battery sign goes away. He couldn't meaning next starter or battery current sensor and then may be ECM which is under warranty.
I suspected ECM and current sensor initially. Fuses and fusible links are ok. The alternator ripple voltage is around 11 mV so diodes are ok i.e. no leaking AC current. 
Just came across your situation and wanted to ask that did you replace current sensor and/or how di you resolve the situation? All ECM reset process remove Engine related DTC, do you know of non-engine related DTC removal process? Please inform, thanks.


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## VStar650CL (Nov 12, 2020)

The LIN communication line from the ECM to the alternator is also shared by the Grille Shutter. Very often a bad shutter will short or clamp the comm line and prevent communication. Check the green wire at the alternator connector or the blue wire at the grille shutter (they're the same wire), it should read around 10~12V. If not, try popping the shutter connector and see if the generator lamp goes out. If so, the shutter controller is dead.


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## anjp (Jul 3, 2016)

I forgot to update this thread...but for my OP issue, it went away around Aug 2020 totally on its own. I did lots of testing but didn't change any parts and it hasn't come back since. 
Really at a loss as to what's going on but am glad the indicator is gone 🤷‍♂️


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## Punasan (12 mo ago)

anjp said:


> I forgot to update this thread...but for my OP issue, it went away around Aug 2020 totally on its own. I did lots of testing but didn't change any parts and it hasn't come back since.
> Really at a loss as to what's going on but am glad the indicator is gone 🤷‍♂️


Glad to hear! thanks for the update and I feel better that what I am thinking going on in my car is the same! I think light came to inform that OEM battery is getting weaker and even after replacement with AGM it stayed on!? Perhaps with drive cycle it may go away once ECM updates data. All other parts and wires check out ok, if not I will first replace current sensor which is lower cost then Alternator. 
Another fellow in TX (hot climate) had OEM EFB battery on Nissan Rogue Sport, battery died without light and upon replacement with AGM no issue at all.


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## Punasan (12 mo ago)

VStar650CL said:


> The LIN communication line from the ECM to the alternator is also shared by the Grille Shutter. Very often a bad shutter will short or clamp the comm line and prevent communication. Check the green wire at the alternator connector or the blue wire at the grille shutter (they're the same wire), it should read around 10~12V. If not, try popping the shutter connector and see if the generator lamp goes out. If so, the shutter controller is dead.


Thanks for your prompt response and hint. The wires checked out for continuity and low resistance. Still i will check what you are suggesting and update here. Today it is chilly here but next week slightly above 32 F so will be checked next week. I think this is the green ground wire you are referencing (see attached)


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## VStar650CL (Nov 12, 2020)

Yep, that's the one. When there are problems with the LIN it's almost always the grille shutter causing the problem and not the alternator.


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## Punasan (12 mo ago)

VStar650CL said:


> Yep, that's the one. When there are problems with the LIN it's almost always the grille shutter causing the problem and not the alternator.


Thanks, one more question to clarify, the diagram is simplified, but in reality i tried to trace it and it seems it is going towards engine block and has black wider jacket for a thin wire!? what do you mean by grille shutter? could it be to ground ALT here on grill on a painted part?
will use this link to look for active grill shutter per attached link in my car 2017 Nissan Rogue Sport and update Active Grille Shutter
and does the following report mean any thing to answer this LIN question?








Also I think you are on the right track from following U1051 DTC








just have to figure out Grill shutter location and trace the green wire with black jacket. Perhaps it could be in vertical line downward from fresh air intake duct which is on drivers side near hard light, some pointers/hint will be helpful. Thanks.


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## VStar650CL (Nov 12, 2020)

I don't have ASIST in front of me today to confirm, but according to Identifix the '17 Qashqai may not have a shutter like the Rogue does. If it exists, it will be where shown in that link. That green wire should run straight to the ECM from the alternator, and if the car has a shutter then there will be a splice inside the harness with a blue branch wire going to the shutter control.

Those codes all indicate that either the LIN wire is open between the alternator and ECM, _or_ the driver circuit silicon in either the alternator or ECM is bad. You can check the wire with an ohmmeter and the pin-fits with an 0.025" safety pin, but if those check out then it's a hardware failure and you should try a new alternator first.


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## Punasan (12 mo ago)

VStar650CL said:


> I don't have ASIST in front of me today to confirm, but according to Identifix the '17 Qashqai may not have a shutter like the Rogue does. If it exists, it will be where shown in that link. That green wire should run straight to the ECM from the alternator, and if the car has a shutter then there will be a splice inside the harness with a blue branch wire going to the shutter control.
> 
> Those codes all indicate that either the LIN wire is open between the alternator and ECM, _or_ the driver circuit silicon in either the alternator or ECM is bad. You can check the wire with an ohmmeter and the pin-fits with an 0.025" safety pin, but if those check out then it's a hardware failure and you should try a new alternator first.


Good Morning! and thanks a lot for this info! The voltage and resistance measurements along with ripple voltage, V with load and without load all show that Alternator with new battery AGM is OK (see attached in-vehicle battery test report). This led to either current sensor or ECM. current sensor turned out ok so ECM. Reset of ECM to wipe off DTC works only if it is engine related and not CHG. I am planning to check all fuses again as I have come across that half burnt fuse may cause such weird warning light. 
I have checked several times V before and after short drives and the battery typically shows 12.8 V before and after. So what is replenishing the Battery? of course the ALT and not causing overcharge so V is regulated, just the warning lamp is not turned off some signal for this is missing. I don't think ECM takes this long to learn (driven with new battery about 80 miles and 10 short drives) that there is a new AGM battery in place of 5 years old weaker OEM EFB battery. Perplexing situation!?


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## VStar650CL (Nov 12, 2020)

The codes mean the alternator isn't talking to the ECM, _not_ that it isn't charging. Nissan "smart" alternators will go into what's called "internal regulation" if they lose contact with the mother ship, basically outputting a fixed 14.2V. So your test result only tells you the alternator is charging, it doesn't tell you if its communication circuit and communication hardware are any good.


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## Punasan (12 mo ago)

VStar650CL said:


> The codes mean the alternator isn't talking to the ECM, _not_ that it isn't charging. Nissan "smart" alternators will go into what's called "internal regulation" if they lose contact with the mother ship, basically outputting a fixed 14.2V. So your test result only tells you the alternator is charging, it doesn't tell you if its communication circuit and communication hardware are any good.


Thanks for your prompt response and explaining it well with an analogy! I appreciate it as it relieves me that alternator apart from (not or poorly) communicating part to ECM, function wise, is doing its job! I also checked in PA DMV safety inspection list if battery warning light is an issue, it may be. Inspection is due in May, so I have time.
Somehow i suspect a bad ECM and Nissan consumer affairs is of no help as they represent dealers and not a consumer! I asked them if my Car falls under the service campaign bulletin (see attached) for bad ECM they cannot even confirm and just say go to dealer. Dealer wants to solve problem by trial and error. I asked him what probability or assurance can he give me that battery warning light will go away with new alternator? he could not. So next could be some another part and so on. I want to avoid this uncertain route. If you can, is this true that ECM cannot be reset for Charging DTC, it can only for Engine DTC? Reason I ask is if I reset ECM (similar to computer reboot scenario) can this communication glitch if it is non-hardware related go away? Assumption is that ECM was trying to notify that the CCA of 5 years old OEM EFB battery were getting weak so with low ambient temperature notified driver with battery warning light. Now with new AGM battery which is non-EFB, ECM has to relearn battery parameters but is trying to match new parameters with old EFB stored parameters. The parameters do not match and hence battery warning light does not go away. However, by now ECM should have learnt that there is a new battery of different type. I question sometime what if I were to replace with an EFB battery, could the battery warning light gone? I don't know. This tells me to at least try to reset ECM and see the outcome. How to reset ECM for non-engine issues is not known to me other than disconnecting battery for about 24 h.
Thanks for your patience in reading all this.


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## VStar650CL (Nov 12, 2020)

No, the codes you're getting indicate a voltage problem in the LIN circuit and not the car generally, so it's unlikely that anything about the battery would effect or cause it. The problem is that the Service Manual doesn't document anything about the signal voltage and format, the "physical values" in the SM for the LIN pin don't even show a nominal voltage. So if the problem is coming from hardware and not wiring, it will be a crapshoot as to whether the alternator or ECM is the culprit. The SM simply says replace the alternator first, and I'd agree with that. Since the LIN is a 1-wire circuit, the diagnosis is pretty straightforward: Ohm the wire, check pin-fit at both ends, if no problem found then replace the alternator, if that doesn't do it then replace the ECM. One thing I'd be pretty certain of is that reflashing the ECM won't help. There's no reason you can't get it reflashed to make certain, but it's probably a waste of time.


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## Punasan (12 mo ago)

VStar650CL said:


> No, the codes you're getting indicate a voltage problem in the LIN circuit and not the car generally, so it's unlikely that anything about the battery would effect or cause it. The problem is that the Service Manual doesn't document anything about the signal voltage and format, the "physical values" in the SM for the LIN pin don't even show a nominal voltage. So if the problem is coming from hardware and not wiring, it will be a crapshoot as to whether the alternator or ECM is the culprit. The SM simply says replace the alternator first, and I'd agree with that. Since the LIN is a 1-wire circuit, the diagnosis is pretty straightforward: Ohm the wire, check pin-fit at both ends, if no problem found then replace the alternator, if that doesn't do it then replace the ECM. One thing I'd be pretty certain of is that reflashing the ECM won't help. There's no reason you can't get it reflashed to make certain, but it's probably a waste of time.


Thanks, so since it is signal i.e. voltage reading communication in LIN then it has to come from interconnected part for this one wire circuit, namely alternator and ECM. I assumed since alternator traditionally is "wear and tear" item, it gets replaced, but not ECM. I think I have to correct my understanding here that since other LIN communications from ECM are "normal and expected" due to absence of other warning lights such as SES or Engine, I understand then it is the "intelligent/smart part" of the alternator could be responsible for putting out or not putting out correct LIN communication V to ECM and hence the battery warning light. I am happy to learn. Thanks for clear and precise explanations!


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## Punasan (12 mo ago)

VStar650CL said:


> The codes mean the alternator isn't talking to the ECM, _not_ that it isn't charging. Nissan "smart" alternators will go into what's called "internal regulation" if they lose contact with the mother ship, basically outputting a fixed 14.2V. So your test result only tells you the alternator is charging, it doesn't tell you if its communication circuit and communication hardware are any good.


Sorry but two more questions:
(1) if communication by smart alternator via LIN (green wire) to ECM is broken, then what tells alternator to stop charging battery once 14.2 V is reached or prevents overcharging of battery ?
(2) role of current sensor at negative terminal ? besides battery temperature monitoring. 
Thanks for the answers.


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## VStar650CL (Nov 12, 2020)

The alternator has a "dumb" internal regulator and reference built-in as a "failsafe" for exactly your situation, in case the smartwork loses contact with the mother ship. The reference is fixed at 14.2V and will behave just like a traditional internally-governed alternator.


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## VStar650CL (Nov 12, 2020)

The current sensor is decoded by the BCM and not the ECM, and the exact parameters the BCM uses in requesting more or less juice from the charging system is another one of those things that are "ill-defined" in the service manual. However, a sensor that's "lying" to the BCM can definitely cause undercharging and unexplained dead batteries. When a known-good battery keeps dying repeatedly and no charging fault can be found, replacing the current sensor is one possible answer


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## Punasan (12 mo ago)

VStar650CL said:


> The alternator has a "dumb" internal regulator and reference built-in as a "failsafe" for exactly your situation, in case the smartwork loses contact with the mother ship. The reference is fixed at 14.2V and will behave just like a traditional internally-governed alternator.


Thanks to you and Auto Engineers designing this "failsafe" system.
Now i know why Service manager at dealer said "put a tape on it", when I said that ECM (since it is under warranty) should be replaced first if he cannot assure that replacing alternator would remove battery warning light. Also a working ECM will diagnose a failing alternator correctly. But somehow he stuck to i think what Nissan SM says replace alt then erase DTC and if it reappears replace ECM. In reality, cost of ALT is greater than ECM and time/labor to replace ALT is longer than ECM.
I have come across some reading/video where on rarely driven cars some disable this terminal 2 green wire at LIN/ECM connector pin 86, so that if one drives for short time or distance the ALT charges the battery. While reading this i was wondering how do they protect battery against overcharge/overheat. Now I understand. 
So in conclusion, if i may ask, letting this battery warning light stay and continue driving is ok? optionally, I do not know disadvantages of using Cen-tech Battery ALT monitor by plugging into power outlet while driving can alert me of real power trouble. Reason for this is as I understood, ALT is ok for charging part, just voltage regulation/communication and receiving commands from ECM that more power is required (i.e. smart part of ALT) is bad. Is this understanding and approach correct? in your experience.


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## Punasan (12 mo ago)

VStar650CL said:


> The current sensor is decoded by the BCM and not the ECM, and the exact parameters the BCM uses in requesting more or less juice from the charging system is another one of those things that are "ill-defined" in the service manual. However, a sensor that's "lying" to the BCM can definitely cause undercharging and unexplained dead batteries. When a known-good battery keeps dying repeatedly and no charging fault can be found, replacing the current sensor is one possible answer


Thanks for well explained function as I could not gather it from reading at this link
Battery sensor: how it works, problems, checking, battery replacement 
i have examined this part and it is free from rust and dirt, except I could not take off negative thicker wire with copper crimped connector nut as it is probably fixed on bolt with thread sealant. I am saving this for warm (so i don't break plastic part in cold) weather project to remove nut and clean the connector if required.


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## Punasan (12 mo ago)

VStar650CL said:


> The current sensor is decoded by the BCM and not the ECM, and the exact parameters the BCM uses in requesting more or less juice from the charging system is another one of those things that are "ill-defined" in the service manual. However, a sensor that's "lying" to the BCM can definitely cause undercharging and unexplained dead batteries. When a known-good battery keeps dying repeatedly and no charging fault can be found, replacing the current sensor is one possible answer


two questions, please explain, following one after another not both unplugged at same time, thanks.
(a) if green LIN wire from ALT is unplugged and car engine turned on? does anything get damaged? Reason to ask this is to see if battery warning light stays on or not?
(b) if current sensor on negative is unplugged and car engine turned on? any damage to circuits?


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## VStar650CL (Nov 12, 2020)

Neither one will harm the car in any way, but the BCM will throw an "open circuit code" for the current sensor in addition to the LIN codes you're already getting because of the alternator.


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## Punasan (12 mo ago)

VStar650CL said:


> Neither one will harm the car in any way, but the BCM will throw an "open circuit code" for the current sensor in addition to the LIN codes you're already getting because of the alternator.


When you first replied your name looked familiar and now I recalled from ******** Forum where during this issue i had read disabling ECM controlled alternator. 
It seems in my case since IC regulator is not communicating and cutting off charging, disabling ALT does not come into consideration. 
This weekend once icy weather is over, I am planning to disconnect current sensor and drive around. I may get "charging message" in addition to Battery warning light but that is ok. My question is what protects AGM battery from overcharging on say long rides 100+miles or 2 hours at stretch? since current sensor is removed, no way to know battery temperature remains normal during such ride or not. is this correct? I know these are newbie questions, but I do not have much expertise in this area. Thanks for your explanations. I appreciate it and did learn few intricacies from your earlier explanations.


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## VStar650CL (Nov 12, 2020)

On Nissans where the "smart" alternator is controlled by the IPDM you can generally disconnect the control wire without getting any warning lights or bad behavior. It's common on Armadas, Infiniti M's and some others. That's because those models use a different control format, PWM versus LIN. On cars like your Rogue which use LIN control by the ECM and not PWM control by the IPDM, you can't disconnect the control wire without getting warning lights. However, the electrical result is the same in both cases, the alternator simply goes into "internal regulation" where its circuitry keeps the output at a fixed 14.0~14.2V. In essence it becomes a conventional, "dumb" charging system. I won't give a treatise on why that won't overcharge a healthy battery, suffice it to say that charging systems literally worked that way for 100 years before computer-controlled systems were even a twinkle in an engineer's eye. Temperature isn't even considered, the car has no means to measure it (or any need). Whether AGM or flooded-cell, it takes a much higher charge voltage than 14V to harm a healthy one.


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## Punasan (12 mo ago)

VStar650CL said:


> On Nissans where the "smart" alternator is controlled by the IPDM you can generally disconnect the control wire without getting any warning lights or bad behavior. It's common on Armadas, Infiniti M's and some others. That's because those models use a different control format, PWM versus LIN. On cars like your Rogue which use LIN control by the ECM and not PWM control by the IPDM, you can't disconnect the control wire without getting warning lights. However, the electrical result is the same in both cases, the alternator simply goes into "internal regulation" where its circuitry keeps the output at a fixed 14.0~14.2V. In essence it becomes a conventional, "dumb" charging system. I won't give a treatise on why that won't overcharge a healthy battery, suffice it to say that charging systems literally worked that way for 100 years before computer-controlled systems were even a twinkle in an engineer's eye. Temperature isn't even considered, the car has no means to measure it (or any need). Whether AGM or flooded-cell, it takes a much higher charge voltage than 14V to harm a healthy one.


Thanks for your details and explanations. This answers my concerns/worries and removes all doubts. For other users i have attached Nissan charging systems pdf as FYI.


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