Jump to content

Low Fuel Indicator

Mulaka

Recommended Posts

GPSilverado Enthusiast

GPSilverado

Posted
Posted
About 3-4

 

 

Hey Rich, do you (or anyone else here for that matter) know how the low fuel indicator is triggered? We have a few HHR's at work for company cars, and they always hit as soon as the fuel range gets down to 50 miles. On my 2009 Silverado 1500 1LT ECRB it seems to vary. I thought once I saw it as low as 25 miles remaining, and then once I know it was somewhere around 35 miles remaining.

 

It really probably isn't important, but I was just curious. It goes with being a Chevrolet technician for 10 years I guess, but I've been out of the business since 1997. If I did know this, I have forgotten LOL.

green river Enthusiast

green river

Posted
Posted

I believe the fuel gauge triggers the light. On my '07 I've had the low fuel light come on and go back off after a few minutes. It seems like it takes a few minutes for the gauge to come up to the correct reading. Sometimes the gauge will be as far off as 1/4 tank. I've also noticed on the DIC that the miles remaining will also climb as the gauge climbs. Hope this helps and makes sense.

MS3DALE Senior Enthusiast

MS3DALE

Posted
Posted
About 3-4

 

 

Hey Rich, do you (or anyone else here for that matter) know how the low fuel indicator is triggered? We have a few HHR's at work for company cars, and they always hit as soon as the fuel range gets down to 50 miles. On my 2009 Silverado 1500 1LT ECRB it seems to vary. I thought once I saw it as low as 25 miles remaining, and then once I know it was somewhere around 35 miles remaining.

 

It really probably isn't important, but I was just curious. It goes with being a Chevrolet technician for 10 years I guess, but I've been out of the business since 1997. If I did know this, I have forgotten LOL.

 

 

Yeah '97 was before they started putting a low fuel level indicator in the trucks (First year was '99 on the GMT800 trucks)

 

This is from SI in GM-GlobalConnect...

 

The fuel level sender changes resistance based on the fuel level. The powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is low and the PCM senses a low signal voltage. When the fuel tank is close to empty (above 15% remaining), the sender resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The PCM sends the fuel level message via the serial data circuit to the body control module (BCM). The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the serial data circuit to display on the fuel gauge. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics. When fuel levels are less than 15% of total fuel level the PCM SWITCHES TO A CONSUMPTION MODE. The PCM stops reading the fuel level sender and instead calculates the remaining fuel level, based on fuel injector rolling counts. This is done to reduce gauge error from fuel slosh. The PCM will remain in the fuel consumption mode until enough fuel is added to raise the total fuel level to 18% or higher. The PCM will resume measuring the fuel level from the fuel level sender after a 45 second timer has expired. The timer is used to prevent driving conditions from momentarily raising the fuel level.

 

The fuel gauge defaults to empty if:

 

• The ECM detects a malfunction in the fuel level sensor circuit.

 

• The IPC detects a loss of serial data communications with the ECM

 

 

FUEL LEVEL LOW

The instrument panel cluster (IPC) illuminates the FUEL LEVEL LOW message in the driver information center (DIC) and the LOW FUEL indicator when the IPC detects that the fuel level is less than a pre-determined value.

When the fuel level is less than a pre-determined value, the low fuel indicator illuminates in the IPC

GPSilverado Enthusiast

GPSilverado

Posted
Posted
About 3-4

 

 

Hey Rich, do you (or anyone else here for that matter) know how the low fuel indicator is triggered? We have a few HHR's at work for company cars, and they always hit as soon as the fuel range gets down to 50 miles. On my 2009 Silverado 1500 1LT ECRB it seems to vary. I thought once I saw it as low as 25 miles remaining, and then once I know it was somewhere around 35 miles remaining.

 

It really probably isn't important, but I was just curious. It goes with being a Chevrolet technician for 10 years I guess, but I've been out of the business since 1997. If I did know this, I have forgotten LOL.

 

 

Yeah '97 was before they started putting a low fuel level indicator in the trucks (First year was '99 on the GMT800 trucks)

 

This is from SI in GM-GlobalConnect...

 

The fuel level sender changes resistance based on the fuel level. The powertrain control module (PCM) monitors the signal circuit of the fuel level sender in order to determine fuel level. When the fuel tank is full, the sender resistance is low and the PCM senses a low signal voltage. When the fuel tank is close to empty (above 15% remaining), the sender resistance is high and the PCM senses a high signal voltage. The PCM uses the signal circuit of the fuel level sender in order to calculate the total remaining fuel percent in the tank. The PCM sends the fuel level message via the serial data circuit to the body control module (BCM). The BCM sends the fuel level percent to the instrument panel cluster (IPC) via the serial data circuit to display on the fuel gauge. The fuel level information is also used for misfire and evaporative emission (EVAP) diagnostics. When fuel levels are less than 15% of total fuel level the PCM SWITCHES TO A CONSUMPTION MODE. The PCM stops reading the fuel level sender and instead calculates the remaining fuel level, based on fuel injector rolling counts. This is done to reduce gauge error from fuel slosh. The PCM will remain in the fuel consumption mode until enough fuel is added to raise the total fuel level to 18% or higher. The PCM will resume measuring the fuel level from the fuel level sender after a 45 second timer has expired. The timer is used to prevent driving conditions from momentarily raising the fuel level.

 

The fuel gauge defaults to empty if:

 

• The ECM detects a malfunction in the fuel level sensor circuit.

 

• The IPC detects a loss of serial data communications with the ECM

 

 

FUEL LEVEL LOW

The instrument panel cluster (IPC) illuminates the FUEL LEVEL LOW message in the driver information center (DIC) and the LOW FUEL indicator when the IPC detects that the fuel level is less than a pre-determined value.

When the fuel level is less than a pre-determined value, the low fuel indicator illuminates in the IPC

 

 

 

 

Exactly what I was asking about. Thanks for the info.

 

That explains why mine turns on at different times regarding range left. I know the time I only had 25 miles left I was towing a fairly heavy load, in rolling hills, at 70mph. I was probably getting 9-10mpg at best.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing
×
×
  • Create New...