ILM-NC G37S

iTrader: (3)

It goes without saying, but I must point out two things that are VERY IMPORTANT to this repair:

1) Be sure to disconnect your battery BEFORE starting this job.

More importantly:
2) The amp has 2 connectors. Take a sharpie marker and MARK which connector goes where BEFORE unplugging them from the amp.

It is VERY easy to mix up connectors for the amp with some from the headunit. Take 2 minutes and mark the 2 connectors for the amp so as not to mix them up when you put everything back togrther. This step will save you from potentially bricking the car.

mikebrah

Alright will do. Thank you so much yet again, hopefully this will resolve everything!!

Breaking my g37

Hey, I also have the P0462 code, I just re-soldered the resistors and reinstalled the amp but my code didn't go out, also at a full tank so I'm gonna run down the gas to see if it fixed my gauge at least, I took my scanner and manually erased the code so ill see if it comes back on, please let me know if replacing the amp clears the code for you so ill know if my amp is faulty or I'm just a bad solderer.
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klenotion

Hey. Have you resolved the issue? I got a 2011 G37x recently and I have a similar problem. It always shows that the tank has more than half even it is small amount.

Breaking my g37

Yes! Resoldering the resistors managed to fix the fuel gauge and my service light hasn’t come back on

The 4 resistors in the middle of the board I only resoldered the 2 but just incase im gonna resolder the other 2, might need a magnifying glass and good light to see the cracks

ro0kie

So I’m having an issue and trying to figure out what it could be before start throwing $$ away.
Long story short, I was having the issue of the amber key light and most of the time couldn’t start or turn off the engine, so like every one else, went to my mechanic, supposedly the issue was the BCM, no fix, then steering lock module, no fix, took it to the dealership, replaced ipdm, half fixed and now I figured out that I had water leaking in and going for the wires and making the car go crazy, so my guess those modules never were the issue.
My concern here is that although my fuel gauge seems to read correctly, the huge fluctuations I have in range it’s just nonsense, after filling up, sometimes shows 373km range and by the end I only make around 280km, last time I filled up I only had 243km range, already did 79km and it shows now 254km range, according to the info in the cluster/screen shows 24L/100km…..but the needle gauge works properly, I think.
I’ve noticed the first 100km the needle drops 1/4 tank so technically it should last around 400km, but nope, once it hit half tank, I get little over 100km with the remaining half tank.
Every morning I turn on the G and let it warm up, everything seems normal, as soon I start driving, just like that 10-15km range just “disappears”.
I have this G for 6 years now and the highest I’ve seen was 15L/100km during the winter since it takes longer to warm up at negative temp.
Already replaced the control unit btw and same outcome, so at this point I’m thinking the sensors.

Joe2000

I tried this but it didn’t work so you have an idea of what it can be

Teichhorn

Not sure if this thead is still alive. Similar issues to other posts about. Normal cluster self check, replaced fuel pump, Driver Side float sensor, AC Amplifier. Fuel guage works not but is very erratic, sometimes 50 mile swings in range with moving fuel level needle. Is this normal? Seems to go to full when topped off. Also had issue with leaking sunroof on BCM. Does Fuel level power come through BCM? Trying to get this behaving correctly and wondering if a BCM fault (no codes) might be causing voltage variations within normal range causing displayed fuel levels.

Thanks,

Tim
2013 G37x

ghost044

It is the ac amplifier or was for me. I did all you mentioned and it was the stupid box

G10

Hello Everyone , I just wanted thank OP @flipmode007 Thank you. Your posting helped me resolve my gas gauge issue and eventually save me some $$$.
I just wanted to point out that i had to take very close look at this before applying solder thanks to harbourfreight i was able to do buy and solder this all in afew hours
Note that you do have to look very closely, using my phone camera and zooming helped me.




Thanks
J

T-Wall

Coming in with another question re: part #'s, quick background:

I have a 2012 G37x, ~120k kms, same issues as many posters; fuel gauge started getting slightly wonky, then very wonky, and now throwing SES light. I'd be fine with just going with trip reset for fuel but the SES light is beyond my ADD tolerance. Looking to replace AC amp as first step before pulling apart fuel system components. I pulled the center console today and found my AC amp part number "27760-1NM7D", and, alas, there are no used parts available with the exact match. Closest I can find is "1NM6D". Having read through many posts, I understand best practice is to replace with an exact match, otherwise various problems can spring up, however:

Would anyone know what the difference is between "7D" and "6D"? If the potential issue/feature loss is something extremely minor I could live with it. If it's playing with fire to go with non-exact match, though, I'll pull it and find someone to solder the resistors.

Any advice appreciated.

flipmode007

Great question, I wont be able to tell you whats the difference but I know that most parts are interchangeable. . All I know, I went to the scrap yard and grab one from a 2010 and mine is an 09.
Anyone can correct me if I am wrong.

T-Wall

Follow-up: I finally managed run the tank low enough without the wife filling it prematurely out of fear (ran out of gas when it started acting up a few months ago) and managed to dump fuel system cleaner into the tank before a fill. Cleared the CEL and went round trip Toronto to Montreal (1,000km) and some other around town driving the last two weeks, 3 fills since the cleaner and things seem to be back to normal.

Hoping it was only some gumming up of the sender units in the tank and system cleaner at every oil change will keep the issue at bay. Will update as things go along.

G10

I guess i spoke too soon, my gas gauge now stuck at 3/4 mark . I have driven 204 miles since fillup and that should put the gague right between 1/2 and 1/4 mark Any suggestion on what i should do to fix this

Thanks

beefychicken

A huge thanks to @BlackG37CT for pointing out the cracked solder joint on the resistor on the AC Amp board!

My story;
Tank ran dry the other day in traffic even though the car was showing a 1/4 tank...
So I had to do the whole coast to a stop, make that phone call ... 'sure it said 1/4 tank Beefy, i trust you...' then filling with a gas can for the enjoyment of every passer-by, etc. : (

-BTW, I almost never run it this low, so who knows how long this issue was baking - although I have been ignoring the P0642 code for about a month. so I am partly to blame.

Anyway, after getting home and vowing to never go below a 1/4 tank again, I ran my issue through the forum search to see what was out there for help and guidance.
And after a first run and skimmimg through the topics, I resigned myself to opening the tank to clean the sending units and locating and saving an AC Amp on eBay for possible future ordering. And priced some sending units at Napa.
But before completely giving in to spending $$, I read a bit deeper into the threads and discovered @BlackG37CT 's post about the cracked resistor joint. A reprieve was offered! And accepted!

So with all the enthusiasm that I could muster at my age, I tore into the dash, expunging it of many vital components, various screws and other unmentionables that happened to be inside there. This activity occuring a mere few hours ago.
And all that effort paid off in a big way. Because as soon as I extracated the Amp and disemboweled it, I found one of the four resistors on the board had a cracked solder joint. Holy poor manufacturing processes, Batman.
I did my best micro-min solder job (will not share that picture...) and put it all back together nearly the way I found it.

Then powered up everything, made sure none of the smoke escaped from the wires and boxes, put away the extra screws for some project down the road and ran it through a nice op check.
Not only did everything work, but the CEL was cleared as well!
I claim victory and accept my points for this round.

Now I will have to do some real world testing and watch my mileage as the needle goes down and hopefully it will dip below 1/4 tank and provide a trust worthy indication.

Time will tell and I plan to update this post with the results.

here is a pic of the bad solder joint.