95 vortec ecm fuse

hey fellas longtime no see, my apologies for not being able to post or reply my job requires me to travel. have a new problem with my truck, it only starts when i remove the ecm fuse and put it back in with the key on engine not running. i have a constant engine light unless i take the ecm fuse out with key on engine not running and replace it then it will turn on but seconds after the light comes on again. i have fuel pressur and spark back in my old post i mentioned i replaced everything in my engine top to bottom so im kind of lost. when it runs the rpm gage jumps around going crazy then it stops, some help if you could since the one guy s.....t on my thread. any help please

anyone here today to give some input

When the check engine light comes on, it's telling you that there is a malfunction. The computer stores the code in memory. Auto Zone and Advance Auto will retrieve the code(s) at no charge. Post the codes here and we will help you diagnose the problem.

hey i got the code its p1345 ignition misfire. i have a new ignition, coil, module, the crank sensor was put in 2years ago, i have new timing chain cap rotor plugs and wires

P1345 is "crankshaft/camshaft sensor correlation". What this means is that something is not aligned exactly right. It could possibly be that the crankshaft sensor is misaligned in its bracket, it may be loose, or it may be crooked. Other possibilities include the timing chain is not correctly timed, (off a tooth) and/or the distributor gear is not timed correctly in the camshaft gear, (off a tooth). P1345 is not a common fault code and it’s typically triggered due to basic engine problems. Your best bet is to obtain a shop manual and follow the flow chart for this DTC.

hey thanks for the tip, that tells me a lot, when my timing chain was replaced the mechanic grinded the crankshaft stud hole using the puller with a coned end instead of using the flat tip, and i think that the damper is coming outward therefor allowing the crankshaft spacer to move forward, thus causing a misalignment with the c. sensor. does this make sense please correct me if im wrong

hey thanks for the tip, that tells me a lot, when my timing chain was replaced the mechanic grinded the crankshaft stud hole using the puller with a coned end instead of using the flat tip, and i think that the damper is coming outward therefor allowing the crankshaft spacer to move forward, thus causing a misalignment with the c. sensor. does this make sense please correct me if im wrong

Yes, or the sensor itself is bad.

hey thanks for the tip, that tells me a lot, when my timing chain was replaced the mechanic grinded the crankshaft stud hole using the puller with a coned end instead of using the flat tip, and i think that the damper is coming outward therefor allowing the crankshaft spacer to move forward, thus causing a misalignment with the c. sensor. does this make sense please correct me if im wrong


BINGO! Yes, that could definitely cause a misalignment. The pulse ring for the crankshaft sensor is part of the damper. If it is not aligned with the sensor, the sensor can not get a correct reading.

guys im going to knock this on its a....ss and post back and let you know what happens. thank fellas you guys are sh......izzle

ok fellas fixed the problem thanks to you guys, your gonna like this one here we go. well i took off the crankshaft pully and harmonic balancer and guess what i saw my harmonic balancer is a two peace held together by a rubber seal, well you know that on the balancer theres a timing mark which should corolate with the mark on the center which is the groov, well they where facing in different directions, it seems like the guy that did my timing chain was banging on the balancer to push it back on the crankshaft and it came apart and when he put it back together again he did not align the center groove for the crank with the timing mark on the outside of the harmonic balancer. this has been kicking my a.....ss for over a year and four months, thanks to you guys for making me go back to that crank sensor. you guys kick some serious a....ssssssssss
this forum is number one baby

the reason the truck started when i removed the ecm fuse is that it resets the computer temporarely once the truck is started the light would come back on. and when i turned off the truck i was back at the first square again

yip, and go get the guy that did the timing chain to fix his crappy work.

hey fellas im back, small problem my ecm ignition fuse is popping every 5or6 days dont know what exactly is the cause, can a bad cap and rotor cause this hit me back

The distributor cap and rotor are not fused. So the answer to your question is no, this will not cause the fuse to blow. There is something else that is shorting out, or for some reason is drawing too much current.

What is the ECM ignition fuse for?

The ECM ign fuse protects the primary ignition circuits.

What would cause the ECM ignition fuse to pop?

Something in the circuit is drawing excessive current. Possibly the ignition coil, or the wiring to it.

I realize that but I am asking why did it pop.

my distributor was out of timing and i fixed it thanks to you guys, but im trying to figure out why my fuse is popping, is it a-coil b-control module c-ignition module

does anyone have a diagram of the ignition wiring please help

Check all wiring going to the coil and check for wear marks or where the wiring can ground out.

On the ‘95 4x4 Vortec the ECM fuse supplies power to the PCM or VCM-A, which in turn provides power to the crankshaft sensor, ignition coil driver, fuel injectors and a host of other things, including most of the sensors on the engine that will have to do with a no start condition.

My ECM fuse (fuse #10) was popping when I engaged the cruise control. (I have no after market anything) It’s a 20 amp fuse and I ran out of 20’s, so I put in a 30 amp and it apparently fried something on the electrical side of the engine, but it didn't blow the 30 amp fuse. (No Start now and no spark) I also noticed it powered the SES light. I’ve been doing some trouble shooting and it appears the VCM-A is not supplying the AC pulse to the coil. It’s still unknown if the VCM was causing the fuse to blow or maybe the coil driver was, or one of the sensors – still trouble shooting.

On the ‘95 4x4 Vortec the ECM fuse supplies power to the PCM or VCM-A, which in turn provides power to the crankshaft sensor, ignition coil driver, fuel injectors and a host of other things, including most of the sensors on the engine that will have to do with a no start condition.

My ECM fuse (fuse #10) was popping when I engaged the cruise control. (I have no after market anything) It’s a 20 amp fuse and I ran out of 20’s, so I put in a 30 amp and it apparently fried something on the electrical side of the engine, but it didn't blow the 30 amp fuse. (No Start now and no spark) I also noticed it powered the SES light. I’ve been doing some trouble shooting and it appears the VCM-A is not supplying the AC pulse to the coil. It’s still unknown if the VCM was causing the fuse to blow or maybe the coil driver was, or one of the sensors – still trouble shooting.

You are lucky you only fried something electrical instead of causing a fire.

NEVER EVER put a bigger fuse in to cure a problem.

You are lucky you only fried something electrical instead of causing a fire . . .
Actually, it would be a blessing if this piece of crap caught on fire, then I could collect on the insurance. Hmmmmmmmmmm . . . . . .:evillol:

almost forgot to mention i was under my truck to the rear where the gas tank is checking stuff out and discovered a ground wire from the gas cap housing to the axle and joined by another ground going to the fuel sending unit and pump it was rotted and in pieces come to find out thats one of the reasons my truck wouldnt start. thats one for all the fellas out there

thats probably what was popping my fuse all this time

If the wire you're referring to is the fuel pump ground, yes, that would stop the fuel pump from running. It will not cause a fuse to pop, ground wires are not fused.

i was wondering if you were here or not, any ideas on why my fuse pops i thought that if the pump wasnot grounded that that was the problem but now im back to square one

i need help with this ecm ignition fuse kind of tricky checked coil, module to coil, wiring to coil, my distributor is new, my timing is on the money, plugs ok, plug wires ok

ok started a new thread on this, hope someone can help, my ecm ignition fuse is popping every 3or4 days but dont know what it is

Chilton and/or Haynes manuals have wiring schematics in them so you can see everything that is protected by that fuse and trace the wiring for a short circuit. If your vehicle is a "late" 95 and equipped with OBDII, PM me with your email address and I'll send you a pdf that covers 96 S&T series wiring. If your vehicle is not equipped with OBDII this schematic will do you no good.


EDIT: You had a DTC P1345, the vehicle is equipped with OBDII.

ok started a new thread on this, hope someone can help, my ecm ignition fuse is popping every 3or4 days but dont know what it is

Most likely a bad ignition switch (common). Sounds like it's grounding out sometimes, then blows the fuse. Replace ignition switch.