View Full Version : 03 Silverado P0540 Error code

07-14-2012, 04:38 PM
So had return lines from injectors tightened and no longer diesel getting into crankcase then next day engine light comes on. Code P0540 shows up as "Intake Air Heater A Circuit". So today talking to mechanic buddy he says mechanic who fixed fuel return lines may have not attached a wire or broke a wire and if I leave it the truck will be harder to start in cold weather... something to do with glow plugs too. So is this an easy quick thing to check? Like can the same gm mechanic or other mechanic figure this out quickly? I live 4 hrs from Hope where mechanic fixed loose fuel lines so I wonder if its something they could check easily\quickly since I'll be driving through on Wed or just wait to take to a shop locally? I'm driving to Abby and back from the Cariboo Wed so maybe get it figured out or fixed while my gf is shopping lol.

07-14-2012, 07:48 PM
Google is ur friend checked the fuse????

07-17-2012, 10:27 AM
the fuse is under main fuse box under hood I was told... I'll try to locate it today.

07-17-2012, 10:59 AM
Ok found 175 amp fuse under fuse box. Power at one end none at other end. I took fuse out and ohm tested in and no continuity so guess its shot. So just ordered one through GM, $20. Hopefully its the only problem...Thanks for the help!

07-17-2012, 11:01 AM
Also to make maters a little more unnerving... truck has been hard to start so I been bleeding a bit of air out of fuel filter and then it finally fires up. Maybe replacing the fuse will solve problem...

07-17-2012, 03:23 PM
you shouldnt have to bleed any air out of a fuel filter to start your truck? there is not alot of ways an electrical fuse will allow air into the fuel. i would be looking for an air leak in your fuel system as this would cause hard starts.

07-19-2012, 09:04 PM
Hooked up scanner, cleared code. Replaced fuse. Engine light dids not come back on. So all good I think. Engine turns over for a second or two before its starts. Seems normal.