fuel sensors

[crankor]

So i finally got a cel for the fuel sensors not working. I tried cleaning them once a while back but didnt fo much, I also was only able to use rubbing alcohol instead of a maf cleaner so not sure i that woukd have made a difference. My question is if anyone knows which sensor is circut A? Im assuming if its tge fuel pumps side that id have to replace the whole pump unit? I remember seeing a video of one guy tgat was able ti get just the top half with the float but said at the time was very difficult to find...

[VStar650CL]

For saddle tanks the sender attached to the pump is always A and the sub-unit is B. However, they're wired in series on the FX (and all the other Nissan products I know about), so the Meter has no way to tell which one is problematic. If one side doesn't read obviously spotty or dead with an ohmmeter, replace both.

[crankor]

Of course that's how it would be. Thanks for the info.

[VStar650CL]

Sorry to be the bearer of bad news, but you're welcome.

[crankor]

I ended up replacing both sensors and the gauge read accurate for 2 days and now its way off again. Shows 3/4 or a tank when i have less than half. Not sure what else could be the issue

I found a video that mentions bad solder connections on the temps control unit... could this be a possibility? I wouldn't have thought that to have a relation to the fuel gauge

[VStar650CL]

Resistance in the circuit will cause the gauge to read emptier, not fuller. You have something rubbing to ground someplace, or your Meter & A/C Amp or gauge are faulty.

[VStar650CL]

I found a video that mentions bad solder connections on the temps control unit... could this be a possibility? I wouldn't have thought that to have a relation to the fuel gauge

PS - Your FX (and a lot of other Infinitis) has a split meter system. The cluster has almost no brains in it, and much of the measuring (including fuel level) is done by the HVAC controller located at the front of the center console. Nissan calls it a "Unified Meter and A/C Amp". So the vids aren't wrong.

[crankor]

Ah good to know. Guess ill take it apart and check bad solder joints. The gauge sometimes is accurate but varies on each start up.

Also a side question related to the fuel pumps I had, I got a supposedly oem fuel pump replacement and either the one that was in the car was not the original or the one I got might not be. Not sure how I would tell a generic from an oem? The new one i got the sensor was more straight vs the one that was in there was slightly curved. I took pictures of the different numbers I saw on the pump but not sure how to verify what it is from that yet

[VStar650CL]

If your gauge read right for a couple of days then the problem isn't an incompatible part for the sender, that would have showed up immediately. Chances are you have a bad cluster or a bad Amp. Like I said, open circuits will make the gauge read emptier, not fuller. Unless you have chafing to ground on the signal wire, a failed component is much more likely than a wiring issue.

[crankor]

I got around to taking out that controller and re soldered some of the connections which so far seems to of helped. But there is now a minor issue I'd the air bag light is now flashing. No idea why its doing that. I didn't think any of those plugs were related to any air bags..

I tried disconnecting the battery but it still shows and im not sure if or where any airbag diagnostics are in my scanner tool

[crankor]

Oh I got it to reset finally. I tried the ignition 4 time trick thing but it didnt work the first few attempts but it worked this time

[crankor]

Update, the gauge for the most part is working fine now. Only maybe twice it read way more than it should. Oddly though, now when I fill the tank and it seems aain when its at half, I get the same cel code for the gauge sensor eve though its working? Maybe theres sill some bad contacts in the controller? I only solders a few... if it was the gauge itself there wouldn't be a cel would there? I woukd think it just straight up wouldn't work if it was a faulty gauge but I dont really know

[VStar650CL]

Yah, the gauge itself wouldn't generate any slosh codes. There's still a problem someplace in your C/U or wiring.