C-5 Fuel Level Sensor 2 Saga
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Joined: May 2007
Posts: 97
Likes: 0
From: Sterling VA
C-5 Fuel Level Sensor 2 Saga
2001 C5
Fuel Guage Intermittently drops to empty. Occasionally resets but usually have to clear the code via the DIC to restore operation. Guage is otherwise accurate.
Tried Seafoam and Techroline blend gas which seemed to decrease the frequency of the guage dropping to empty but did not eliminate it.
Had Independent shop look into the problem. They replaced both sensors with GM OEM parts. Now the guage indicates only between 3/4 and full. Still occasionly drops to empty and throws the Fuel Sensor code.
The Independent caught wind of the TSB on a software patch for fuel gauge issue and contacted the local Chevy dealer to install the patch. The ECM turned out to be locked and the Chevy dealer said the computer would have to be replaced.
The ECM was replaced with a unit that included the most recent patches yet the fuel gauge issue displaying between 3/4 and full persisted. Independent was unable to solve the problem.
Took the C5 to the Chevy dealer this morning for a separate Emissions Inspection problem. They looked into the fuel guage issue and found a Service Bulletin (#PIC3275A -Document ID 1777138) with good news and bad news. The Good News is they seem to have found the actual problem and have a fix. The Bad News is the cost of the ultimate solution.
It seems the current fuel level sensors provided as OEM replacements may have a mechanical interference problem when used with the original right side fuel tank shipped with the vehicle. In my case that may very well account for the reason the fuel guage displayed between Full and 3/4 when not going to zero after replacing the fuel level sensors.
Oddly rather than revisit the sensor the Bulletin instructs the tech to replace the right side fuel tank and not attempt to munipulate the SENDING UNIT FLOAT ARM. Of course replacing the fuel tank is going to cost big bucks.
Anyone experience this before and if so is there a more economical alternative short of selling the Vette to the Yankees?
Fuel Guage Intermittently drops to empty. Occasionally resets but usually have to clear the code via the DIC to restore operation. Guage is otherwise accurate.
Tried Seafoam and Techroline blend gas which seemed to decrease the frequency of the guage dropping to empty but did not eliminate it.
Had Independent shop look into the problem. They replaced both sensors with GM OEM parts. Now the guage indicates only between 3/4 and full. Still occasionly drops to empty and throws the Fuel Sensor code.
The Independent caught wind of the TSB on a software patch for fuel gauge issue and contacted the local Chevy dealer to install the patch. The ECM turned out to be locked and the Chevy dealer said the computer would have to be replaced.
The ECM was replaced with a unit that included the most recent patches yet the fuel gauge issue displaying between 3/4 and full persisted. Independent was unable to solve the problem.
Took the C5 to the Chevy dealer this morning for a separate Emissions Inspection problem. They looked into the fuel guage issue and found a Service Bulletin (#PIC3275A -Document ID 1777138) with good news and bad news. The Good News is they seem to have found the actual problem and have a fix. The Bad News is the cost of the ultimate solution.
It seems the current fuel level sensors provided as OEM replacements may have a mechanical interference problem when used with the original right side fuel tank shipped with the vehicle. In my case that may very well account for the reason the fuel guage displayed between Full and 3/4 when not going to zero after replacing the fuel level sensors.
Oddly rather than revisit the sensor the Bulletin instructs the tech to replace the right side fuel tank and not attempt to munipulate the SENDING UNIT FLOAT ARM. Of course replacing the fuel tank is going to cost big bucks.
Anyone experience this before and if so is there a more economical alternative short of selling the Vette to the Yankees?
Instructor
Joined: Dec 2012
Posts: 229
Likes: 2
From: Charleston South Carolina
sounds like two different problems with the fuel gauges...
1- gauge shows between 3/4-4/4 without going to full completely. This seems indicative of the above problem with the sender and mechanical interference on right side tank.
2- the fuel gauge shows full and then sometime during use drops to E for a period of time before returning to the correct reading again later. This appears to be the sulphur issue and between Techron treatments (poor in tank 1/4 or less to allow mixing and sharing between both right and left fuel cells)....and then the TSB from Chevrolet...it fixes it.
am I missing anything between the two being similar but unrelated?
1- gauge shows between 3/4-4/4 without going to full completely. This seems indicative of the above problem with the sender and mechanical interference on right side tank.
2- the fuel gauge shows full and then sometime during use drops to E for a period of time before returning to the correct reading again later. This appears to be the sulphur issue and between Techron treatments (poor in tank 1/4 or less to allow mixing and sharing between both right and left fuel cells)....and then the TSB from Chevrolet...it fixes it.
am I missing anything between the two being similar but unrelated?
Melting Slicks
Joined: Mar 2004
Posts: 2,404
Likes: 408
From: Horseshoe Bend ID
There are about four kinds of fuel senders. Long Arm, Short Arm, Pre-FFS and Post FFS. Some even have the same part numbers. You have to make sure you get the right part number for your fuel system. Also, it is easy to cause interference when installing the sender, it can rub the side of the tank or hang up on the fuel sock. Have the shop re-install the parts.
