GM 2.4 sensor question for a mechanic

[brocsbar]

1999 grand am 2.4 ....what sensors prevent the injectors from opening ?? Will not enuf pressure also not open them?

[thephantom1492]

is the security light flashing?

[brocsbar]

no flashing lights only a ucode u1040

[thephantom1492]

U1040: Loss of Class 2 Communications with ABS

That could indicate a problem with the wiring, maybe the BCM can't send the password to the PCM, so it do not enable the injectors...

[brocsbar]

or it could be the fuel pump and that code doesn't mean much right?

[thephantom1492]

it could be the fuel pump.

But sure thing is that you have a serious issue with the abs, which mean it probably disabled, which mean that the car have a security feature that do not work, whick mean the car is not road legal right now.

[brocsbar]

not worried about abs right now UNLESS it is stopping injecters from opening. I guess next week I'll put my otc injector cleaner in line with the fuel line and put the right psi to the rail and see if it starts and if it won't then I'll know the injectors aren't opening. I'll post back so everyone will know if this u-code will stop injectors from opening.

[brocsbar]

just bypassed fuel pump with injector cleaner canister at 60 psi right after fuel filter. (With key on no fuel came out of pump) but that shouldn't matter as I was suppling the fuel right to the line.
did Ign module and plugs boots , cam and crank sensor and the fuel filter was clogged bad. But i don't see what is keeping it from opening the injectors. I have 12 v puling at injectors so r they just plugged that bad? that ecbm code is the only code i got. It will run for a second with a shot of ether so its got spark. I'm stumped? where is the modules? 1040 code is all it has?????

[doctorhrdware]

Originally Posted by phatom1492

U1040: Loss of Class 2 Communications with ABS

That could indicate a problem with the wiring, maybe the BCM can't send the password to the PCM, so it do not enable the injectors...

I agree with thephantom1492. This is how the system usually works.
The injectors will have +12Vdc always supplied to one side of the connection on the injectors. The other side of the connector which is the ground is controlled by the PCM. Since there is a communication issue, that would indicate that there is a wiring problem. I think that is why the injectors are not opening.

[danielsatur]

There is a fuse for the injectors!

An ''Out of Car Injector Service'' is best.
Any diesel shop can micro bath, blowout, and test the flow rate.
A signal + clicking noise doesn't rule out a bad injector.

[doctorhrdware]

If the fuse was blown, but then wouldn't the +12Vdc at the injectors be missing?

[brocsbar]

good point plus i checked the fuses

[brocsbar]

if the computer supplies ground to the injectors when all systems are a go, is it posible to wire up a ground for the injectors and bypass the computer sending ground? I still don't have fuel pressure though....i hate these cars

[brocsbar]

when i turn the key to acc all the lights are on including security and then i try to start it and no flashing security(while starting), and when i stop trying to start and return the key to acc then there is no security light. is this normal? Also while it is trying to start the guages jump around all funny. but the car doesnt start then die it just doesn't start.......

[brocsbar]

i don't think pump cause i supplied 60 psi to fuel rail with injector cleaner tool and still no start. Even blew out lines with air.....will start with starting fluid and die (but doesn't start and die with key just won;'t start)
I had a gr am 2.4 that would start and die right away and it was the airbag module under seat messing things up but this is a different animal it seems. No fuel pressure but still won't start when fuel supplied is what is stumping me. I will be here checking every hour for input or to answer ?s cause this mechanic is bound and determined to get to the bottom of this.