S430 Fuel Guage innacuracy.
Thread Starter
Joined: Apr 2007
Posts: 3
S430 Fuel Guage innacuracy.
I had to change my "Rear Sam?" because of some water damage I had gotten under the back seat, on the passenger side. This had made my fuel guage not work, or any power go to the rear. I had changed the SAM, and now everything works, even the fuel guage. But then I kept on driving, the guage needle would move, but it is innacurate. It would tell me there is like 18G in the car for about 250miles of driving. And when I fill up the car...The needle will stay all the way down, as if it was not working, then after about 50 miles of driving, it will shoot all the way up.
Someone had said it is my Sending Unit. Another had told me it was a fuel relay?
Has anybody had this problem, or know about it and can tell me what I can do to fix this...
It is a 2000 S430.
Thank you!
Someone had said it is my Sending Unit. Another had told me it was a fuel relay?
Has anybody had this problem, or know about it and can tell me what I can do to fix this...
It is a 2000 S430.
Thank you!
Senior Member
Joined: Dec 2004
Posts: 2,410
From:
RE: S430 Fuel Guage innacuracy.
Hi,
From yourdescription the tank sender unit appears high on the list of suspects.
However, what is the history behind this failure.
Was it working before you lost ALL (please quantify) rear end electrics?
Strange you should have two failures at once.
From yourdescription the tank sender unit appears high on the list of suspects.
However, what is the history behind this failure.
Was it working before you lost ALL (please quantify) rear end electrics?
Strange you should have two failures at once.
Thread Starter
Joined: Apr 2007
Posts: 3
RE: .
What should I tell my mechanic to do? Should I just replace the Fuel Sending Unit? or is that not going to change anything if the coding in the rear SAM is messed up. Or should I just tell him to Re-Code....im guessing or re-program the SAM if that is possible...
My fuel guage used to work properly until the rear SAM was damaged, and when I replaced the SAM, The rear tail lights started working again...Because there was no power going to the rear at all because of the damaged comp. Now that I replaced it, I have all power back in the rear, and there is power for the fuel guage...But it just doesn't read right....And when I fill it up, it wont read at all until about 40 to 50 Miles into my drive.
Please let me know what I should do....Thank you!
My fuel guage used to work properly until the rear SAM was damaged, and when I replaced the SAM, The rear tail lights started working again...Because there was no power going to the rear at all because of the damaged comp. Now that I replaced it, I have all power back in the rear, and there is power for the fuel guage...But it just doesn't read right....And when I fill it up, it wont read at all until about 40 to 50 Miles into my drive.
Please let me know what I should do....Thank you!
Senior Member
Joined: Dec 2004
Posts: 2,410
From:
RE: .
It appears that the SAM MAY need to be coded and it is behaving "strangely" because the unit has insufficient or incorrectparameters to send the correct signal to the fuel gauge.
Coded means "programmed" to match your vehicle.
The SAM you have purchased is a generic part and MAY fit to many models and markets of MB and needs to be "set up".
This requires connecting to a STAR (MB proprietary) or similartype of diagnostics computer to carry out the procedure.
Connecting to such a computer will also enable On Board Diagnostic codes to be read which should assist in pointing towards the problem by identifying that parameters are missing or implausible for the Vehicle Identity Number VIN etc.
Stuart.
Coded means "programmed" to match your vehicle.
The SAM you have purchased is a generic part and MAY fit to many models and markets of MB and needs to be "set up".
This requires connecting to a STAR (MB proprietary) or similartype of diagnostics computer to carry out the procedure.
Connecting to such a computer will also enable On Board Diagnostic codes to be read which should assist in pointing towards the problem by identifying that parameters are missing or implausible for the Vehicle Identity Number VIN etc.
Stuart.
Junior Member
Joined: Mar 2017
Posts: 1
I had to change my "Rear Sam?" because of some water damage I had gotten under the back seat, on the passenger side. This had made my fuel guage not work, or any power go to the rear. I had changed the SAM, and now everything works, even the fuel guage. But then I kept on driving, the guage needle would move, but it is innacurate. It would tell me there is like 18G in the car for about 250miles of driving. And when I fill up the car...The needle will stay all the way down, as if it was not working, then after about 50 miles of driving, it will shoot all the way up.
Someone had said it is my Sending Unit. Another had told me it was a fuel relay?
Has anybody had this problem, or know about it and can tell me what I can do to fix this...
It is a 2000 S430.
Thank you!
Someone had said it is my Sending Unit. Another had told me it was a fuel relay?
Has anybody had this problem, or know about it and can tell me what I can do to fix this...
It is a 2000 S430.
Thank you!
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