2003 Silveardo Gas Gauge

[sreilly77]

Hi all. I know that the gas gauges on the Silverados have always been troublesome due to faulty sending units. But I'm not sure if the issue I'm having has to do with a faulty sending unit.

When I start my truck in the morning, the gas gauge reads empty. However the moment I start driving, the gas gauge begins reading again at the correct level of gas in the tank. When I come to a light and sit for about a minute, the gauge then reads empty again, and moving again, it begins reading correctly again and remains in the correct position until the truck becomes stationary again.

I replaced the fuel pump assembly two years ago. I just started having a problem about a month ago, and I have not been using the truck as frequently as I had before. It's a 2003 with 219,000 miles. I've pulled the pump and checked the sending unit, the pump, and the wiring and everything seems to be ok. Could anyone lend any insight on what the problem could be? May be a ground wire I missed or something? When the gauge reads empty, the "Fuel Level Low" message appears on the dash, so I can rule out a bad gauge cluster (which I replaced last year due to a faulty speedometer).

Thanks in advance!

[j cAT]

Originally Posted by sreilly77

Hi all. I know that the gas gauges on the Silverados have always been troublesome due to faulty sending units. But I'm not sure if the issue I'm having has to do with a faulty sending unit.

When I start my truck in the morning, the gas gauge reads empty. However the moment I start driving, the gas gauge begins reading again at the correct level of gas in the tank. When I come to a light and sit for about a minute, the gauge then reads empty again, and moving again, it begins reading correctly again and remains in the correct position until the truck becomes stationary again.

I replaced the fuel pump assembly two years ago. I just started having a problem about a month ago, and I have not been using the truck as frequently as I had before. It's a 2003 with 219,000 miles. I've pulled the pump and checked the sending unit, the pump, and the wiring and everything seems to be ok. Could anyone lend any insight on what the problem could be? May be a ground wire I missed or something? When the gauge reads empty, the "Fuel Level Low" message appears on the dash, so I can rule out a bad gauge cluster (which I replaced last year due to a faulty speedometer).

Thanks in advance!

your problem is what I have now and back to when the 2000 silverado had 38K miles on it. same exact problem .. tap on the bottom of the tank forward section and the gauge will pop back to the fuel level in the tank.. another test is place the tranny in neutral and have the vehicle roll then hit the brakes most times the gauge will pop back up again.

surprised with a fuel pump replacement this happened .. what was the pump # used and who made it ?

I still have the OEM 2000 pump assy.......

[DeltaP]

Did you replace the entire pump/sender assy or just the pump? What I find on high mileage, class 8 road tractors that I work on is the float arm develops excessive axial play due to wear at the pivot. This causes poor and intermittent contact with the rheostat, or variable resistor in the sender/pick up assy.
With the truck running in the morning and while the guage reads empty rock the vehicle up and down and sideways. Then check the dash guage. It might just be a worn sender assy. JMHO Your mileage may vary.

[sreilly77]

Originally Posted by DeltaP

Did you replace the entire pump/sender assy or just the pump? What I find on high mileage, class 8 road tractors that I work on is the float arm develops excessive axial play due to wear at the pivot. This causes poor and intermittent contact with the rheostat, or variable resistor in the sender/pick up assy.
With the truck running in the morning and while the guage reads empty rock the vehicle up and down and sideways. Then check the dash guage. It might just be a worn sender assy. JMHO Your mileage may vary.

I replaced the entire pump/sender assembly. When I do rock the truck back and forth in the morning, the gauge does begin reading correctly again. I can check the pins on the sender assembly and see if they have broken or may be bent.

[sreilly77]

Originally Posted by j cAT

your problem is what I have now and back to when the 2000 silverado had 38K miles on it. same exact problem .. tap on the bottom of the tank forward section and the gauge will pop back to the fuel level in the tank.. another test is place the tranny in neutral and have the vehicle roll then hit the brakes most times the gauge will pop back up again.

surprised with a fuel pump replacement this happened .. what was the pump # used and who made it ?

I still have the OEM 2000 pump assy.......

I can't remember what the pump number was, but I know it was OEM. The issue started happening when my truck began to sit during the week because my company gave me a work truck to use. Before then, I never had an issue. But as mentioned, when I rock the truck back and forth, the gauge does begin working again. That's why I was beginning to believe that there was possibly a ground issue.

[j cAT]

Originally Posted by sreilly77

I can't remember what the pump number was, but I know it was OEM. The issue started happening when my truck began to sit during the week because my company gave me a work truck to use. Before then, I never had an issue. But as mentioned, when I rock the truck back and forth, the gauge does begin working again. That's why I was beginning to believe that there was possibly a ground issue.

the ground issue will effect the fuel pressure before the gauge operation.

the rocking causes the rheostat arm to move which then cleans off the pick up.

when you replaced this fuel pump did you have to splice in a new connector ? if not then you may have installed the old GM pump that has these issues with the alcohol fuels causing the oxidation of the rheostat contact strip to send the level info to the dash ............and PCM.....

if you purchased the airtex pump then you would be lucky to get 1 year out of it.

[DeltaP]

if you purchased the airtex pump then you would be lucky to get 1 year out of it.



Man I sure learned that the hard way!

[sreilly77]

Originally Posted by j cAT

the ground issue will effect the fuel pressure before the gauge operation.

the rocking causes the rheostat arm to move which then cleans off the pick up.

when you replaced this fuel pump did you have to splice in a new connector ? if not then you may have installed the old GM pump that has these issues with the alcohol fuels causing the oxidation of the rheostat contact strip to send the level info to the dash ............and PCM.....

if you purchased the airtex pump then you would be lucky to get 1 year out of it.

I did not have to splice in a new connector. The new pump assembly was plug and play.

Truck does have 220,000 miles on it, so I'm not too worried about it. I haven't had the time to take the bed off and check the pump. It's supposed to be a warmer day on Sunday here in the Northeast so I'll take a look at it then. I'd hate to replace the whole assembly since the pump is still working just fine. May be I can try and clean the contact strip with something not too abrasive. If not, I guess I'll just live with it until this pump fails.

[j cAT]

Originally Posted by sreilly77

I did not have to splice in a new connector. The new pump assembly was plug and play.

Truck does have 220,000 miles on it, so I'm not too worried about it. I haven't had the time to take the bed off and check the pump. It's supposed to be a warmer day on Sunday here in the Northeast so I'll take a look at it then. I'd hate to replace the whole assembly since the pump is still working just fine. May be I can try and clean the contact strip with something not too abrasive. If not, I guess I'll just live with it until this pump fails.

if you are the original owner , and the wiring to the fuel pump connector at the top of the fuel tank was not with a wiring splice job then you put in the GM defective pump that was used over 10 years ago. the new GM/AC DELCO replacement pumps require the new connector to be soldered into place . to plug into the now improved PUMP , the sender which is the issue of these old silverado vehicles. cleaning the strip will get it to work for a short time. many have done this just to make sure it was the sender strip. using TB/electric cleaner will clean it up . NO ABRASIVES..