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Category: Dodge
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Experience:  ASE Master certified, ASE certified Undercar Specialist, ASE Advanced Engine Performance certified
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I have a 2002 dodge ram 1500 2wd 5.9. the ECM black wire is

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I have a 2002 dodge ram 1500 2wd 5.9. the ECM black wire is grounding out the ignition coil and wont let it start. The green wire has 11.9 volts when cranking. Ive replaced the ECM,Crank sensor,cam sensor, battery, ignition switch, alt and coil. Can any one give me any ideas
hello and welcome to Just answer!

please explain in detail what you mean by the PCM is grounding out the black wire.

Here is what is supposed to happen. You have 2 wires going to the ignition coil. One is dark green/orange and the other is black/gray. the dark green/orange wire should have 12 volts when the ignition is on. Make sure you have 12 volts. The PCM then grounds the black/gray wire to fire the coil. If you back probe the black/gray wire with a test light connected to 12 volts, it should blink the light when cranking the engine. if it does, and you are sure you have a good ignition coil, try replacing the coil wire that runs from the distributor to the ignition coil. I've seen these wires go bad quite often.

If you have no pulse on the black/gray wire and you do have power on the dark green/orange wire, you will need to check the black/gray wire between the PCM and the ignition coil for shorts to ground or open circuit.

Sounds like you have replaced all the parts associated with getting spark. Do you know if you have injector pulse? Run the tests and let me know.

thanks! I'll send this through as an answer in case this solves the problem but rest assured I'll be here to help further if need be.
Customer: replied 7 years ago.
When I crank the motor I get 11.9 volts between the bl/grey and green/or wire. but when its plugged in I dont get anything out of the coil. Ive replaced the coil with 4 different BW coils with the same result. When I oham the primary side {where the wires plug in}of the coil it goes to 0 ohams. If I oham it through the pri to sec wire I get the readings that my manual spec's. If the pri side has a direct short between the two this would ground out the 11.9 volts and not let the coil spark. Ive replaced the wire going to the dist. cap also.
you should not get a steady 11.9 volts with your volt meter connected across the 2 wires. the PCM pulses the ground on the black/gray wire so your meter should be quite all over the place during cranking. If you connect your leads across the 2 wires key on not cranking do you get a reading?
Customer: replied 7 years ago.
No I only get voltage when cranking. But when the primary is plugged in to the plug it goes in on the coil is ohamed it reads 0 ohams when tested it doesnt matter what setting i use on my multi meter. Wouldnt this ground out the 11.9 volts because when I oham the Black and grey wire to ground it goes to 0 ohams. Ive traced this wire back to the computor and it shows it fine
If your black and gray wire has continuity to ground when not cranking, it's either shorted to ground somewhere or you have a defective PCM.

If this is the case, disconnect the PCM connector and see if the black wire still has continuity to ground. If not, PCM is bad. If so, wire is shorted somewhere to ground.
Customer: replied 7 years ago.

Yes the black wire thats going to the PCM when plugged in is shorted to groung. When its unplugged its clear. Send me back and Ill except the answer. Thats what I figured. a new PCM is on the way. Thanks


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we are



we fly to.

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