I have a 92 GMC Suburban C1500 with trouble code 54

[fatsog123]

My Truck is running but the idle goes up & down every other minute.When I try to Put it in reverse it stalls out.I have to let off the brake a little in order too catch it.I was going to change the fuel Relay today to see would that work.If anyone could share their experience with this,it would be nice.

[shorod]

That code appears to be specifically designed to detect issues with the fuel pump relay. You should check your system voltage with the truck idling, as well as with your foot on the brake pedal. It sounds like maybe your system voltage is dropping too low with the extra load of the brake lights (shifting to reverse) and may be causing the relay to open. Post back after replacing the relay and let us know what you find.

-Rod

[fatsog123]

I just replaced the relay,haven't started it yet.I want to change my brake booster first because I hear a hissing sound from it,under the dash.That leak probably put a strain on the start up.Plus,the previous owner had the remote amp wire connected to the red wire on the radio.After I get the booster in I would post my progress.It will take a few days after I order it.Stay with me shorod.