No Power to Coil

Jtreamer · January 30, 2016

Hello! I have a GMC sierra 1500 2wd with the Vortec 4.3 in it. The truck has no spark. I pulled the wire that powers the coil and tested it with a test light and it has no power going to it ( I did do this with the key in the on position.) I checked all the fuses and all of them seem good. I have replaced the ignition control module, ignition switch, distributor cap and rotor, and crankshaft position sensor and the coil is new. I checked the wires at the plug in and they are not frayed or anything. The coil is still not getting any power. There is a p0335 code which seems to be a crankshaft position sensor malfunction but like I said I replaced it and I checked to see if there is power going to the crank sensor with a test light and there was. I am out of idea's, if anyone can help that would be great! Thank you!

tbarn · January 30, 2016

Year?

Jtreamer · January 31, 2016

Hello! I'm sorry I forgot to add the year lol. It is a 2003

tbarn · February 1, 2016

When you say "The coil is still not getting any power", do you mean that there is not 12v on the pink wire at the coil?

Jtreamer · February 1, 2016

exactly, no 12v to the pink wire.

Jtreamer · February 4, 2016

Update:

I now have power to the coil! It was a fuse, i must have looked over it when i was checking them. although there is still no spark out of the coil and im not sure why. I have tried multiple coils now.

citydriver · February 7, 2016

Does the "Check Engine Light" go "ON" when you turn the ignition on? Can you hear your fuel pump energize when the ignition is first turned on? It should go on for a couple of seconds and then shut down if the engine hasn't started. If not, double check your fuses again, the ECM/PCM is probably getting power if it's setting a trouble code, but that's a couple of the first things I check. I don't remember if all 2003's came with VATS (Vehicle Anti Theft System) Is the "SECURITY" light on or flashing when you're trying to start it?....Also, as a precaution, NEVER use a standard test light on any of the computer/module circuits. A digital multi-meter or LOW IMPEDANCE test probe should be used to check module circuits to prevent damage to the computer/modules. You may also want to consider getting a repair manual with diagnostic flow charts to help you diagnose your problem. alldataDIY.com is one source that I use, it is a subscription service as most are, but for me, it's cheaper than throwing parts at a problem. I hope this helps

Jtreamer · February 8, 2016

Hello citydriver! Thank you for the information, I am for sure looking into that alldata, it looks very helpful! thank you for showing me that. I did hook a fuel pressure gauge up to the fuel rail and it was showing 60psi, so the fuel pump seems to be doing its job. The check engine light does stay on when the key is in the on position. I do not think there is any sort of theft system on this truck it is VERY basic no power windows, no power locks, and it does not have a keyless entry. Also thank you for the tip on to not use a test light on the computer circuits I will use my voltmeter next time.

Jtreamer · February 17, 2016

I got her working! I hooked up the Verus scan tool and i looked on live data and during cranking the engine speed said 0, so that told me that the crankshaft position sensor was screwed up. I replaced it again, and boom she fired right up. Must have been a faulty crank sensor