Battery warning light

Let's start with the idea of what a fusible link is. Basically, this is a fuse that is made out of wiring. What happens is when the current is too high this section of wire will break first before any damage to the other wiring will happen.

So, it is a fuse just not a traditional looking fuse. So, the way these normally fail is they get high resistance before they actually break.

So, if you have the warning light on, then this link could have high resistance which means it is robbing voltage from the system and the light will come on.

The way to test this is to check the resistance (ohms) from the battery cable to the IPDM. See the wiring diagram below.

Here is how you do this testing:
https://www.2carpros.com/articles/how-to-use-a-voltmeter

Next, the current sensor could be the issue. Basically, this sensor is doing nothing more than measuring the current that is returning through the negative post so that it can measure the overall state of charge of the battery.

This is a very likely cause of this issue. I attached the testing below on how to check it.

Please run through this info first and let us know what you find, and we can go further.

Thanks

Dear Kenny K,

Thanks for the detailed response!
The continuity test showed continuity between ECM and Alternator harness connector and there was no short to power and short to ground
So, I think the fusible links should be, okay? is that correct?
I will check the current sensor as you suggest and will report back the findings.
Thanks again, I appreciate your help. Have a nice evening!

Question: HPCM = Hybrid Power Control module but my car is gas powered so where would I see HPCM for Current sensor and also, I checked fuse/relays and cannot see terminal 69 and 70? could you please clarify. thanks.

The 2.0L for this year was a hybrid engine so it has a gas-powered engine, but that engine just powers the electric side. So, you should have this hybrid engine if you have the 2.0L unless you have the sport model which I did not check the first time.

Since I am guessing you have the sport model and non-hybrid engine, I am attaching the charging diagram below for that engine

As for the continuity test, this is actually not correct.

You are correct that there is no break in the circuit so the fusible link is not "blown" like a fuse would blow. But that does not prove that there is not high resistance.

Basically, this is the same test as a continuity test except instead of just checking to see if you have a connection/continuity, you are checking how much resistance is in the circuit.

You need to have very low resistance in the wiring so that all your voltage is used where it is supposed to be used in the circuit.

So you check this by putting your meter leads at both ends of the circuit and measure the ohms. If should be less then a half ohm which means the wiring is not only intact but also not high in resistance.

Sorry and thanks, my mistake. Maybe i thought I had written that the car is 2017 Nissan Rogue Sport (2 L gas engine, AWD), as i also cut and pasted what i had written in Nissan forum which provided till todate no help. (As FYI, Nissan Tech info site needs subscription for tech bulletins which I do not have. So I go by general and other web info. The manuals of Nissan do not even give image of fuse box, so I removed each fuse box covers and taken photos for future reference.)
Yes, your explanation of continuity does not equal low resistance makes sense. I will check and report here.

Sounds great. Yes, we have access to all the online manuals and can provide screenshots or anything we need so let us know what you find and then if you have other issues, feel free to start a post on that and we can provide the manual info if you need it.

Basically, we just keep each post to one issue so that others can find the info in the future if they search for the same thing you are dealing with.

Thanks for the update.

Here is the latest update:

1. Battery V = 12.87.
2. Battery V with car running = 14.23.
3. Battery V with car running, lights on, A/C on, heat on = 14.2.
4. Resistance between +ve Terminal and Alt bolt covered by rubber boot feeding wires to +ve Terminal fuse links = 0.01 or 0.02 ohms.
5. same wire shows continuity of 1.

Based on these, I assume that Alternator fusible links, and alternator is okay. What I do not know is AC current leak for the alternator.
Since I do not have a hybrid model I do not know where to find Terminal 69 and 70 to test current sensor. Or please inform me if the following is correct to measure current sensor?
with engine off, remove negative terminal, connect jumper cable to unpainted bracket as ground and other end on negative battery post. Now check voltage between negative terminal battery post and terminal connector removed where harness is connected.
Have a nice, relaxed Sunday evening!

Yeah. That is fine for the wiring.

Here is the testing that we need to do for this specific vehicle.

The battery sensor can be tested this way, but I would check resistance between terminal 1 and 4 and the 2 and 3.

Thanks for your prompt response. one question to verify,
you mean these terminals 1 through 4 of current sensor? Where would I find it? Isn't it at the negative terminal on battery?
As initially I said in the post, I think it could be the current sensor? or I think a malfunction/bad ECM?

Is this the one Main Current Battery Sensor - Nissan 294G0-C990C at negative terminal which has wire harness plugged in? Earlier I had unplugged to see if the pins were clean or dirty, and they were clean but did not measure resistance, as I saw them clean.
Should it be tested for resistance by removing from negative terminal of the battery?

Also, as FYI, I have read this article during troubleshooting
https://www.samarins.com/glossary/battery-sensor.html

I still am hoping that if I drive around closer to 100 miles or so the ECM may relearn that i have a new battery. I have driven small distances around hometown for typical grocery runs etc. (As in NE we have snow and chilly temperatures.) At first, I thought maybe it is QashQai rebranded which was launched in EU and hence maybe I have to register/establish battery in system using Nissan Consult system. However, it is not to be registered, so I think Computer ECM has to relearn that there is a new battery and take away the warning which appeared when OEM battery was about 5 years old and CCA were falling below specs and ambient temperature was.

As additional info the attached battery test at neighborhood AAP store using Midtronics CPX900. The Tech associate entered rating of 550 CCA vs 650 CCA (does this impact test result? I don't know as it is just the baseline value. True?). Earlier on old OEM battery I had seen ripple V of 21-23 mV and here with new AGM battery ripple voltage is 11 mV. (So no/negligible AC current leakage?)

Okay. That is good. Can you get a picture of your negative battery terminal?

The battery sensor should be attached to the negative terminal.

Please see attached image of negative terminal. Because of 4 wires, I think there are 4 pins, I will verify soon but in order to test do I remove the terminal by disconnecting/loosening the bolt on negative post and then check resistance between 1 and 4 and 2 and 3?

That is correct. 2 and 3 are for the battery temperature sensor but we should check that as well.

You just undo the connector from the sensor and then measure across the sensor terminals.

Resistance measurement at negative terminal connector pins, without disconnecting from battery, just removing 4 wire harness plugs. I tried to match wire colors from harness plug order to pins but besides pink, light blue, light green, the white didn’t appear maybe it is beige.
Assumption of Pin order and wire color
(a) From front of Car assuming the order of 4 pins (wire color, see photos) as:
1 (pink), 4 (light green), 2 (white/beige), 3 (light blue)
range 200K ohms selected
Resistance between 1 and 4 = 1
Resistance between 2 and 3 = 94.2

(b) From front of Car assuming order of 4 pins as:
1 (pink), 2 (white/beige), 3 (light blue), 4 (light green)
range 200K ohms selected
Resistance between 1 and 4 = 1
Resistance between 2 and 3 = 4.9 or 5.0

With lower range of 200 ohms on multimeter, all measurements were showing only 1, not changing at all for both pins order (a) and (b) above
When probes of multimeter were touched together it was 1.7

Note: resistance measurement of pins due to on terminal and as pins are sitting inside was little difficult with point probes of multimeter. I tried to put coffee stirrer plastic straw on tip to make error free but the bare probes worked better.

Therefore,
I am not sure if I have measured it correctly. Please inform me and I will check again.
I tried to remove the negative cable but the nut was tight and due to low ambient temp didn't use force, so the plastic part does not break.
Could it be better to measure resistance by taking terminal off the post?
Thanks for your continued help, I appreciate it.

The pins on the first one were correct. 1 is pink, 2 is white, 3 is blue, 4 is light green.

If you checked 1 and 4 and had 1 ohm of resistance, then that is concerning as it is not what I expected. However, let's circle back and make sure we didn't miss the basics which is the 5-amp fuse in the dash junction block.

I attached the info below. Let's just make sure this is not an issue before we replace the battery sensor.

Thanks, and just clarifying, I had checked fuses marked with red lines (in fuse list photo) where (BAT) is written in bottom row (towards floor of car) with shining flashlight through mini fuse for unbroken wire inside.
Question 1.
Is the fuse circled in blue which says 5A meter (IGN) should be checked? I will check this in the morning and inform you of the result.
Question 2:
I think in fuses photo the topmost row are spare fuses, correct?

I confirm the fuse 5A meter (IGN) is intact.
Just a question, I don't mind checking, but if IGN=ignition fuse was out, how come my car was starting and I was driving. This is why I had only checked BAT=Battery fuses as mentioned above.
Just to rule out other possibilities, I want to remove bolt of negative terminal on current sensor assembly (Nissan 294G0C990C) and reassemble by again testing the 4 pins resistance, this time taken off the negative post of battery. What are your thoughts? Please inform me along with next steps. Thanks for your time and help.

That is correct. This fuse is for the ignition switch control in the ECM. So, if that fuse were an issue, then the ignition switch would not work.

As for what you are thinking, I like the idea. However, I suspect we are down to a battery current sensor.

The way to confirm it is using a scan tool that can monitor the ECM data and see what it is reading as the battery state of charge.

Thanks, please see attached image of self-diagnosis result and OBD codes, it points to an issue of ECM I think with U1040 DTC. A question, is it advisable to reset ECM? by touching both terminals (after removing from respective posts) to bleed Capacitor? I don't know if the current sensor is bad then it will again show up as battery warning light, but if it is retaining somehow memory of old OEM battery current state then by this time or in these many drive cycles it should have been re-learnt or re-written?!
With due respect to professionals, Dealer wanted to replace Alternator first and then maybe current sensor and then maybe ECM. This is trial and error, in older cars without ECU/ECM, the battery icon meant charging or alternator issue but with ECU/ECM it could be corrupt memory so like laptop/pc a reboot may be necessary. Of course, this is my personal opinion based on logic.

You can definitely try the capacitive discharge. This is when you remove the cables and touch them together.

However, just to make sure we are on the same page, all the sensor does is measure the current that is flowing through the battery. This is how the sensor can calculate the battery state of charge.

On modern vehicles this info is sent to the ECM, and it helps determine charging needs. If the sensor is not accurate then it can cause the battery light to come on.

However, the light coming on is because the ECM is seeing the charging system/overall system voltage is low. This could be due to an actual issue that it is low, or it thinks it is low which could be a sensor or ECM issue.

If you had the alternator load tested and it passed, then I would go with the sensor at this point.

Kenny thanks for all your efforts! As you can see my first post in #9 I had suspected and asked the question of current sensor. But there were no OBD codes. Shouldn't there be P0517 DTC code? on Self-diagnosis for BCM there is no DTC
On self-diagnosis of ECM, I do not see Battery state of charge DTC (from researching various code #s with my limited understanding or ignorance),
My logic wants to investigate if a reset or capacitive discharge yields which result. Will this harm the situation is my question?
I can even disconnect both terminals and not connect back to battery for about 24 h (that is remove battery out of system for 24 h), will this erase Key Fob codes for normal operation? Also, I have OEM remote start on key FOB will that work?
or what would be erased out which is needed for normal driving of car?
I understand ECM will have to relearn some engine parameters but that is ok, I have patience. However, I do not grasp or understand the drawbacks of such reset or capacitive discharge. Without any strings attached if you could give your insight or point me in right direction I am happy to educate myself.
I just made a grocery and hardware store short trip of about 10 miles and other than battery icon on dash everything including heat, turn signals etc ran smooth. This thing is really perplexing for me.
I will read up on how current sensor goes bad perhaps with high current and then is there no surge/spike protection? really confusing! BTW is this the correct part # Nissan 294G0C990C for the identified issue? Please inform when you can. Thanks.

A battery disconnect does not wipe the memory of modules. It just discharges the modules so that they are forced to restart.

Meaning it is like a complete power off and back on like a cell phone with an issue.

It will wipe the small things that are not programmed into modules like radio stations, but this is called keep alive memory.

It will not wipe key data or any other programmed features.

I totally understand where you are coming from, so I am here to answer all your questions but, in my experience, if it is not the battery sensor then we missed something.

Kenny thanks for your patience and response. I have already identified the part and it will be an easy install. I will give an update here after I try adding more drive cycles and then a reset.
The reason I want to try more drive cycles is because in the link given earlier the article said that:
"in some vehicles, if the sensor has been disconnected or the battery has been replaced, the Stop-Start feature might not work for some time, until the computer (BCM or PCM) re-learns the parameters of the battery."
In my case I had about 5 years old OEM EFB battery and the battery warning light came on and I replaced it with not an EFB but with an AGM, hence maybe the system is taking time.
This article also says what Kenny you said earlier that scan is better than resistance measurement.
"Some require measuring the resistance between the sensor pins, others advise using a scan tool to test the sensor. "
Since I do not have a scanner (other than self-diagnosis report which did not show the current sensor DTC), I will remove current sensor and -ve terminal, clean and make sure it is dirt free not just visual but by air/dust remover similar to PC circuit board cleaning. If this does not work, then definitely a new part.

Okay. Thanks for the update.

Yeah. I think we need the sensor, so I am curious to see what happens.

However, maybe I overlooked it before but the fact that you put an AGM battery in never registered.

The fact is, AGM is just a different construction and material and can be used on any vehicle. However, can you confirm this was an issue prior to the replacement of the battery?

The glass mat battery is simply less internal resistance which is what gives it its' better performance so it should have no effect on this but if this all started after the replacement, maybe something is happening with the current sensor and that battery.

Some times I like to repeat what I say earlier because we all are busy and not as close like the person who is facing the issue. I will definitely update the outcome here.
Yes, first time I got battery warning light on Jan 1, it was raining and car was parked outside garage. I completed an errand/a short ride.
I started battery search on Jan 2, found out original OEM battery was discontinued by Nissan and the replacement battery with different part # 999M1-NBH5A in my area was backordered with dealers. I guessed it is Group H5 from part #. Nissan has not published specs like dimensions and CCA on this. During my work travel in AL, stopped by at a dealer and got the sizes measured and it was 600 CCA. It indeed is Group H5 (BCI 47) so bought this and replaced.
When I got battery warning I examined the terminals and connections all were clean, checked relevant fuses and measured V with and without load. Also got it tested at neighborhood Advance Auto store, everything passed but low CCA, so put it on a trickle charger, drove for a week and again everything passed except lower CCA. So with peak of Winter and low temps here in Northeast decided and replaced with AGM Battery. This is the first Carwhich consumed lot of time for finding appropriate Battery as even Interstate site does not show replacement battery available for 2017 Nissan Rogue Sport or QashQai. So I went by group/BCI and replaced with H5(47) AGM battery it worked. Except the Battery Warning light is still lingering. Then I thought because it is Europe model rebranded for USA may be I have to establish or register, but dealer does not know, although some Nissan dealers mention establishing or registering Battery using Nissan Consult computer. The Nissan dealer I went to wanted to solve it by trial and error by first replacing Alternator, then may be something else and then may be ECM. All I asked the dealer, what assurance can he give me that with Alternator Battery light warning will go away and he could not. I know that there is nothing wrong except may be Current sensor or something simple communication or ECM itself can be bad (based on Nissan Rogue/Infiniti forum).
So long story short, to answer you, it did not start after putting AGM battery. I checked with another person in Nissan forum, in TX region, he replaced OEM EFB with another EFB and no warning light before or after. In his case battery was dead before replacing and no battery warning light for old battery.
Costco where I bought battery had only AGM another far away Costco had H5 EFB and I wonder, if I were to replace with EFB would the battery light gone. Well, this is a great learning experience for me.

Got it. Thanks for that clarification. That gives me the confidence to know if it is not the battery. I couldn't understand how that would be the case, but odd things do happen.

And you do confirm no battery registration required after replacement (like in BMW or VW)?

Correct. There is no registration required. The only thing it states is the erasable memory will need to be relearned with are clocks, radio, and emissions monitoring information.

I appreciate the confirmation. It is better to confirm than realize later that key FOB or some hard programmed memory got wiped off! or radio got locked out or needs an unlock code.

Update: could not remove negative terminal nut after leaving it sprayed with WD40. will try different penetrating oil/solvent which will not attack plastic part, maybe the nut is fixed using some thread sealant. No major rust noticed. Cleaned still Battery light on.
to replace with new part if nut doesn't come loose will cut wire and use another crimped copper terminal end, looks like there is some slack in wire so it will not be short.
Questions:
1. this wire could be bolted to chassis and underneath the triangle shaped fuse box?
2. Please see attached self-diagnostic report attached again, can you point where CHG/Battery current sensor may be listed as error? or it does not have to be and captured under something else?

Sorry. I should have asked for the codes long ago. These are pointing to the issue.

Let's start with the U1040 and U1044 which I have attached below.

Basically, it is saying that you have a wiring issue or an ECM issue.

Take a look a the testing below. Please run through this info and let us know what you find. Thanks

Perfect! and this completes the circle! My original post said that I tried to convince dealer that since alternator is without fault, based on U1040 which is first DTC on the report and it has 3 different reasons in general based on general web search and they all point to faulty ECM. So if ECM is faulty what good a new alternator would do?
Dealer is trying to explain me that Nissan troubleshooting says first replace alternator and then ECM (or in my opinion dealer may say something else say starter, current sensor and then ECM). This is all "trial and error" solving the issue of Battery light warning!
This is one of the reason I still feel that ECM does not register that there is not an EFB but AGM battery. I still wonder what if I were to replace EFB with an EFB, would battery light would have gone by itself? i don't have a back up EFB or another vehicle that will allow me to test this hypotheses.
I still feel ECM (assuming it communicates properly and is without fault) continuously monitors and write new information so after certain number of drive cycles will overwrite new AGM battery parameter (or give up displaying battery error light). (may be a wishful thinking!)
In UK some users of QashQai have faced that by replacing horn fuse under hood of 15 amp the light went away. Since the car horn is working, I do not think it is the case here.
That leaves now resetting ECM (by certain sequence of accelerator pedal pressing). I spent morning looking for low cost OBD II scanner which allows Battery charging analysis, real time preferably! haven't found one. Cannot afford Consult III system.
Coming back to U1040 and U1044:
(a) continuity exists in harness (please see attached)
(b) in absence of hi-tech tools that wipes DTC, do you think resetting ECM (by acc pedal sequences) would clear up Battery warning light?

(c) Based on self diagnosis at CRNT=current time
Nissan Codes on Jan 20, 2022 (at CRNT=current time during diagnostics) this is what I understand that ECM is the issue here.
U1040 NISSAN code possible causes
• Faulty Engine Control Module (ECM)
• Engine Control Module (ECM) harness is open or shorted
• Engine Control Module (ECM) circuit poor electrical connection
U1044 NISSAN code possible causes
• Faulty Generator
• Generator harness is open or shorted
• Generator circuit poor electrical connection
U1051 NISSAN code possible causes
• Faulty Generator
• Generator harness is open or shorted
• Generator circuit poor electrical connection
• Faulty Engine Control Module (ECM)
Please inform, and thanks for all your help. Also no OBD II codes at a store (see attached photo)

Do you think unplugging ECM harness and re-plugging can clear out this error?

It says they are active/current so no. We need to go through the testing because according to that you either need an alternator or an ECM.

If the shop said you need an alternator, they probably found these codes and did this test so they may be correct, or I may be thinking of a different vehicle. Either way, we need to do that testing.