Truck was turned over on side blowed ecm fuse replesd it truck run good for 15 min then died now no fuel pressure at all fuses all good

the pressure regulator controls the power requirement to the fuel pump
when pressure is reached , it allows power/circuit to the ECM to be broken which in turn stops the pump relay from working
when the pressure drops , that circuit is energized and the ECM switches on the circuit , to the relay allowing power to the pump to supply fuel to get the pressure back up
for the circuit operation you will need a schematics of the electrics for the vehicle ( workshop manual) as some may not use the ECM but go straight from the pressure regulator to the relay through a fuse

if the injector fuse is blown then the car won`t start as its not getting fuel into the motor to fire.if the fuse keeps blowing then you could have an injector/s that is drawing too much or the injector driver in the ecm may not be any good and needs replacing or a used ecm.it could be a short some where in the wiring for the injector system that is going to ground.

Check the fuses, I had one a while ago that kept blowing one of the ECM fuses. There are 2 ECM fuses one also sends power to the fuel pump too. Do you hear the fuel pump run when you turn the ignition switch to on? Just turn the key to the "on" position, not all the way to start, you should be able to hear the fuel pump run for about 3-5 seconds. I think it takes a 15 amp, I showed the owner which fuse it was and it would blow occasionally. One day it blew one right after another so he put a 30 amp in, he was out of 15's. I told him that was not a good idea. Anyway, that fixed it he drove it home and put a 15 amp fuse back in it, it's been good ever since.

just fixed this problem, change your fuel pump module, fuel sending unit shorts out on fuel level swing arm blue wire... unfortinately you must replace it as unit because of the design, fuel pump and tank guage fuel level sending unit are a one peice item, fuel tank has to come out to change unit, about a $ 700.00 repair too... fuel pump module runs about 350 to 700 $ depending on aftermarket or factory, try to find one with a lifetime warranty even if it is $ 50.00 more worth it..labor is about $ 250 to $ 400 depending on shop labor rate... definate problem though I ahve no doubt, common problem on GM... please rate my help, thanks...

Oil pressure switch is the last item that could cause this. That system operates on a ground, a short would give you an erroneous gauge reading. You, or a shop, will need to trace wiring on the power side of the computer. a ground there (or in the computer itself) will cause the fuse to blow. a short on the sensor side will give you bad information to the computer, and cause running issues but generally not cause a fuse to blow.
In order to do a proper diagnosis you will need a good volt/ohmeter, a good schematic and a lot of patience.

that red wire is a test lead to jumper the fuel pump to test it.if ecmb fuse keeps blowing my guess is your ecm has a short in it,in that case it can be purchased at oreillys

The ECM-B fuse is a 20 amp fuse, and you should NEVER put a larger fuse in to try to overcome any problem. The oil pressure switch is a secondary concern; there is an idiot light or oil pressure guage in the dash to alert you to oil pressure problems. Under heavy load, such as towing, your engine requires more fuel, and if your fuel pump is going/has gone bad, it cannot supply the demand.
The problem is almost certainly a fuel pump wire harness short, caused by a dying fuel pump. I have both had this problem myself, and repaired it on three other vehicles. On my vehicle, the wire harness had welded itself together when the fuel pump locked up, and the wire harness caught on fire.
The fuel pump is in the gas tank (of course my tank was full), and the tank has to be dropped to access it. The wire harness is modular, with plugs at both ends, and can be bought from the Chevrolet or GMC dealer.
If you put an incorrectly-rated fuse anywhere in your vehicle's electrical system, the WORST place to do it is where you have--the fuel pump circuit. Fuses blow for a reason, and the manufacturer's engineers properly size the fuses for the application at hand. Please don't do that again.
This can be a very dangerous problem and repair, and no, it is not cheap.
Do not attempt to operate this vehicle until you have had the problem properly corrected. Good luck.

it will not blow when ECM is disconnected, cause there is no power to the injectors when you disconnect the ECM. When you turn ignition on check for fuel pressure at fuel rail. Release pressure at nipple on fuel rail. If no pressure exists puel pump is shot. If there is pressure your fuel filter might be plugged.

The first thing you should do is to locate the oil pressure switch/sending unit.


This switch serves two functions.

1) provide oil pressure reading

2) disable the fuel pump relay in event of oil pressure loss.

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When this switch is failing to provide the correct pressure to the ECU. The wiring harness can overheat and eventually create a short.

ECM B blow is because the harness is grounding/shorting.

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DO NOT drive the truck until you change the oil pressure switch.

After you change the switch,you should spend sometime to inspect the wiring between the fuel pump relay,ECU and fuel pump.


Please post up day on the comment window/page.

I will follow up on it later.


Good luck.

please.. 1991 chevy lumina..mech has car for 4 days..
repl ICM.ECM..checked ..all fuses.cranks..no run..smell fuel.
says spark good.Fuel press @ 42. put light on fuel injec sensor
..tells me weak signal( light shud be brighter) .Says it ran once
in 4 days for 2 min & died..." tells me injectors not accepting fuel