120 Grande fuel gauge and rear suspension faulty , electrical or?

[BigNoodle7 Lurker Find all posts View Profile Close BigNoodle7]

Hi I’ve just joined as found Pradopoint helpful in the past. I have a 2004 120 grande with 190k on clock. One rear airbag was replaced 2yrs ago with standard toyo bag so no mod, lower control arms front replaced as well as all bushes 12mths ago. 6mths ago the fuel gauge started doing random things, full- empty-90l full half etc. resetting the car (on off) generally fixed it as I knew the tanks were full so no issues. 6 weeks ago I was driving and rear end was bouncy as hell, stopped and H-N-L function wasn’t working also bags were empty rear end low. Reset car and suspension back on and H-N-L works again. Went to shops today and rear was raised normally parked but when started to drive bouncy rear again and the fuel gauge switched to 90L then full so it seems both issues are linked. Mechanic wants to take dash out and send for diagnostic but seems expensive without knowing the issue. The two issues are definitely linked from my own monitoring so maybe a central control issue or electrical fault. Any thoughts or ideas appreciated.

[Guest Close Guest]

I doubt they are linked. I would be swapping out both rear airbags as you obviously have an issue there. The fact its sinking when parked says you have a leak and its likely a bag.
Then look at the wiring and senders for the senders in the tanks.

[BigNoodle7 Lurker Find all posts View Profile Close BigNoodle7]

Thanks for the reply piggy, one airbag has been replaced and they stayed inflated for days on high low setting. The deflation is intermittent and when inflated can deflate after driving. It’s an intermittent fault as can be fine but then deflate so not a physical issue.

[Guest Close Guest]

It will be an airbag fault, at the age and Kms it will have perished rubber. Meaning random deflations, textbook diagnosis, been there a few times and done that.

[Hobes Junior Member Find all posts View Profile Close Hobes]

I would be checking the Air bags as Piggy has said, age and Kms I would replace airbags myself as a pair if it where mine.
The tank gauge may require you to use down to the low fuel light and then a complete full tank 165l ish to allow software to recalibrate, as partial fillings while may be economic sense at times, play havoc with the fuel level sensing calibration, if this does not stabilise the gauge, I would be looking at earthing/wiring issues and then replacement.

[BigNoodle7 Lurker Find all posts View Profile Close BigNoodle7]

Thanks hobes, it’s been a few more days/weeks now and the airbags are physically sound despite age of vehicle as one is less than 24mths old so not aged or worn and other was replaced earlier. I agree the two are separate issues now with more data. The suspension issue is electrical or controller as it can be fine for days, it can even hold air and be fine overnight only to start the car and it deflates? Restart and it inflates and all Is good. It’s very intermittent and restarting car can create or fix the problem so not a bag issue.