[Solved] Renault Clio 4 Battery Charging Failure Issue: Alternator, Sensor & Error B120F-81 Solutions

I have had a problem with the message "Battery charging failure" for some time. An electrician (apparently the best one in Zielona Góra) dismantled and checked the alternator and the regulator, they are operational but he did not deal with the fault - he gave up. To be sure, another 100% efficient alternator was installed in the car - all cables were also checked. The battery is also installed new. The current sensor on the negative terminal of the battery has also been replaced. The error still appears a few moments after starting the car. Charging the battery is (about 14 V) I have been driving for the second month with this message without problems from the discharging battery. Cruise control, the "Start / Stop" system and air conditioning are not working (but this may be another reason). The diagnosis shows the error "B120F-81 alternator UPC line". Has anyone had a similar problem and how did they solve it?

New battery assigned to the controller?

żałosna udręka wrote:

New battery assigned to the controller?

I replaced the battery at an authorized service station, so I think they did.

LIN bus to the alternator to be checked. Alternator postponed all complete?

żałosna udręka wrote:

New battery assigned to the controller?

No relation - there is NO such thing in CLIO IV.
There are not many possibilities.
As szymitsu21 wrote, first checking the LIN bus - if the LIN cable is 5v-10v with the ignition on, the LIN is theoretically functional.
The weight of the body remains to be checked,
later, an alternator - which has supposedly been replaced with a functioning one.
And finally, the alternator control module - UPC.
If that doesn't help, a wizard, a witch with a cat, or another fairy

The alternator replaced in its entirety, it is said to be 100% functional, but I am slowly beginning to have doubts. Maybe someone knows where in Zielona Góra they will reliably check the regulator?
So far, I measured the voltmeter from the alternator side on the LIN bus to us about 12 V from the UPC driver side, only about 3 V. Unfortunately, I do not have an oscilloscope to check something more and the state analyzer (fake Saleae) may not withstand above 5 V. I ordered myself "Usb LIN converter ", then I will be able to check something more.

I have done 3 similar cases. Three had a defective regulator.

Only the original is involved.

axmarek wrote:

from the alternator side on the LIN bus we have about 12 V from the UPC driver side only about 3 V

I am not sure now (I measured maybe twice) but it seems to me that the voltage on the LIN should be 5-10V on the fastened components

genek1000 wrote:

axmarek wrote:

from the alternator side on the LIN bus we have about 12 V from the UPC driver side only about 3 V

I am not sure now (I measured maybe twice) but it seems to me that the voltage on the LIN should be 5-10V on the fastened components

according to Wikipedia, the LIN bus is 12 V

Welcome back.

The fight continues. Today, in one of the workshops, they checked the alternator for me - it is working, communication after the LIN is working properly, the alternator can be controlled with a tester.

I myself started to check the alternator - UPC cable and it turned out that someone had already rummaged with it (it was cut and soldered at the UPC plug), but still it is functional - there is a transition. The UPC itself was also already unscrewed by someone, the seal was broken and the pin from the alternator cable was marked with a marker. None of the electricians who rummaged around the car on my behalf did it. So the problem must have happened before, but someone has managed to get it. Visually, no damage is visible behind the UPC panel.

The only thing that comes to mind is a damaged UPC module. Can someone suggest what the replacement procedure is ???

Look for the EMM T4 module marked the same as yours - i.e. the equipment version (marked from L1 to L3) and the reference number after the word RENAULT and there is a good chance that there will be no problems.
Ideally, someone would rewrite the contents of the old module for you.

axmarek wrote:

according to Wikipedia, the LIN bus is 12 V

The signal potential is 12v and the signal is square and variable depending on the data transmission - the meter measures the average value of this signal, hence the information that the voltage measured with the meter in the range of 5-10V is correct.

genek1000 wrote:

Look for the EMM T4 module marked the same as yours - i.e. the equipment version (marked from L1 to L3) and the reference number after the word RENAULT and there is a good chance that there will be no problems.
Ideally, someone would rewrite the contents of the old module for you.
\

Thanks for the information.
The module has already been purchased, waiting for delivery. If I change the module without rewriting the content and something goes wrong, I will not cause problems in other modules and immobilize the car ??? Will I be able to insert the old module later to return to the previous state ??? What hardware do I need to rewrite the content?

Quote:

Will I be able to insert the old module later to return to the previous state ???

Yes, nothing will happen.
What is this UPC on?

Hello.

Today I exchanged UPC for those purchased on a well-known auction site. And it's still the same - battery charging error and check the start / stop system. Now I am left with a sorcerer, a witch with a cat (I have a cat but my wife does not want to be a witch), and another fairy . Tomorrow I will come to see what smart computer diagnostics will say.

UPC is on the SPC560P54L3, I could have read it wrong because the disc is covered with some resin and the markings are not readable.

One more question, but this is another matter - in the fuse box under the hood there is something marked with a diode symbol - see the photo - I have it inserted as in the photo and it seems to me that I saw photos on the net where this element is inserted the other way round. Can someone confirm how it is to be pressed. I will add that when measuring with a meter, it does not look like a diode, unless it is damaged.

Has anyone checked the charging on the disconnected alternator plug?

enricofatal wrote:

Has anyone checked the charging on the disconnected alternator plug?

About 14V is connected / disconnected without any difference with the load (lights, air supply, rear window heating) or without a load, it keeps the charging even.

strange thing, the rope steered alternator should not wake up by itself
I haven't seen it yet

Added after 7 [minutes]:

anyway, tomorrow I will check I have a few Reno alternators, I will see how they behave

Quote:

strange thing, the rope steered alternator should not wake up by itself
I haven't seen it yet

It's normal.

today I checked the alternators from some Reno May BSS protocol, but it will not wake up by itself
I checked others on the rope and lin1 also does not arouse
I still have reno alter. valeo I do not know what car but it writes on the housing at the com regulator plug pin.
however, nothing is detected by the normal signal +, i.e. L
but I controlled it via PWM, I changed the voltage value, I met in (citroen peugeot)
of course he woke up himself

Today, unfortunately, I did not get to the diagnostics :cry:

The alternator I have installed is the Valeo TG12C124 controlled by LIN 2.1.
So I thought that maybe the signal cable from the alternator to the UPC is worn and short-circuits with another from the bundle. When I checked the continuity of the cable, I did it with the battery disconnected and I did not think about this possibility. Tomorrow I will measure this wire more closely.
Can someone confirm that the air conditioning failure may be due to a battery charging failure? Because there are no problems with air conditioning in diagnostics and this, unfortunately, does not work. I do not want to go to air conditioning specialists as I am not sure because they will charge me "for nothing".

rather, the climate has nothing to do
I'm surprised why it wakes up by itself on a disconnected plug
understand that this alternator is new in the car and was everything okay in the past?

Added after 6 [minutes]:

just like that. I checked tomorrow, I will compare the numbers I have

enricofatal wrote:

rather, the climate has nothing to do
I'm surprised why it wakes up by itself on a disconnected plug
understand that this alternator is new in the car and was everything okay in the past?

I wrote earlier that the alternator was replaced. The old one is functional too. I bought the car 6 months ago and for four months everything was ok. I don't know the history of the car because I bought it from a dealer who brought it from Belgium. I did not write about it before. Year of production is 2013

physically, when you checked this alternator, you were also able to see that it detected the alternator protocol
anyone had an adapter for alternators on com?

Added after 5 [minutes]:

important cable from the alternator to the pcm, however, the rope protocol can also be connected to other controls in the car
nap. another driver, if something fails on such a cable, it is different with the control

enricofatal wrote:

physically, when you checked this alternator, you were also able to see that the protocol from the alternator was detected
anyone had an adapter for alternators on com?

So I was personally when checking out. The tester shows what the connection protocol is. In the case of my alternator, the socket is marked as COM but the transmission is LIN2.1. Using the tester, you can set the output voltage.

ok and rather lin1, please check this cable as this

I had a similar problem in Qashqai 1.2 turbo petrol J11 .... they managed to do the ECU reflash and described it as restoring the controller to the factory condition ... and the problem appeared after the engine was overhauled ...

Problem solved !!!!

Out of nowhere, 12V appears on the alternator-UPC cable with the ignition on. I disconnected the factory cable and pulled the makeshift and the problem was gone, there was no battery charging error, start-stop and the cruise control works. Air conditioning not very much (today it is quite cold to judge it) but this is probably another problem.

To sum up, on a working bus, the meter shows about 10 V.
The USB Lin converter I bought for bus diagnosis works and you can eavesdrop on what is happening on the bus.

You can see that there are messages with two IDs on the bus, the data changes after increasing the speed. He concludes that there is nothing else connected in the car on the same wire. Anyway, today I have made several dozen kilometers and everything works.

I changed the battery unnecessarily - the old one is functional
I unnecessarily bought and replaced the alternator and the current sensor located at the battery. I probably also bought UPC unnecessarily.

and everything is clear, it's just a cable and you can make such a mess, computerization
it wasn't like it used to be

axmarek wrote:

Out of nowhere, 12V appears on the alternator-UPC cable with the ignition on. I disconnected the factory cord and pulled a makeshift and the problem was gone,

axmarek wrote:

To sum up, on a working bus, the meter shows about 10 V

And now I will write "I told you so"
You had to listen to uncle genek as he wrote that the voltage on the LIN bus should not be higher than 10V and seriously, I would check the installation.
A short circuit to + 12V is not of itself.
The alternator LIN cable has no other connection anywhere - only to the UPC. The cable from the alternator goes through the connector in the bonnet box - the one with the blue clasp - to the cabin, to the white connector on the bulkhead wall next to the clutch pedal attachment.

axmarek wrote:

in the fuse box under the hood there is something marked with a diode symbol - see the photo - in my case it is inserted as in the photo and it seems to me that on the net I saw photos somewhere where this element is inserted the other way round. Can someone confirm how it is to be pressed. I will add that when measuring with a meter, it does not look like a diode, unless it is damaged.

If you have a diode inserted, as in the photo, you have it on a short circuit - it probably is not a diode anymore
This LED is used to "extinguish" the A / C compressor clutch solenoid coil and is wired in parallel to the clutch.
Inserted the other way around makes the power supply shorted from the relay to ground, so I would check the 15A compressor fuse next to the main plus screw.

genek1000 wrote:

And now I will write "I told you so"
You had to listen to uncle genek as he wrote that the voltage on the LIN bus should not be higher than 10V and seriously, I would check the installation.
A short circuit to + 12V is not of itself.

Yes, the installation can be checked and I will do it. Thanks for the tips on how the cable is going.

genek1000 wrote:

If you have a diode inserted, as in the photo, you have it on a short circuit - it probably is not a diode anymore
This LED is used to "extinguish" the A / C compressor clutch solenoid coil and is wired in parallel to the clutch.
Inserted the other way around makes the power supply shorted from the relay to ground, so I would check the 15A compressor fuse next to the main plus screw.

Until I went to check and indeed the fuse is blown (well, normally a clairvoyant some kind: please . Previously, I checked the fuses, but I had to omit this one or not notice that it was blown. Could this solve the problem of non-working air conditioning ??? Genek you are great!