No spark!

Hi,

If you have no spark, it could be several things. With that in mind, we need to check a few things. First, if you have a live data scan tool, see if there is an RPM signal when cranking the engine. If you don't have a scanner, pay attention to the tachometer to see if it moves a little when cranking.

Next, if you go to the ignition coils, you will find they all should have power when the key is in the run position. At each connector, there will be either a red wire with a green tracer or a red wire with a white tracer. Those are the wires to check for power. The power comes from the same power supply, the ECM relay, and before the relay, fuse 42 in the power distribution module under the hood.

If there is no power, go to fuse 42. In addition to checking the fuse, confirm there is power to and from it. Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If that checks good, then confirm the relay is good. If there is another relay with the same part number, switch them. If there isn't, here is a link that explains how to test one.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

On the other hand, if you do have power to the coils, confirm the common ground they all share (black wire) is good. You don't need to locate the ground (top front of engine) but instead, confirm continuity to ground at each black wire on each coil connector.

If that is good, they have power, and the crankshaft position sensor is sending an RPM signal, there is a chance the PCM itself is bad. The PCM provides a ground path to each coil to fire it.

I attached the entire wiring schematic for the powertrain management system below. I highlighted the wires I mentioned above specific to power supply. Also, I thought you could use this as a reference point.

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below. Note: The schematics were four pages long. I had to cut each pic in half to make them readable for you. I did, however, overlap them so you can follow from one to the next.

Hi,

If you have an RPM signal, the crank sensor is working. Since you have power to the coils, check to make sure the PCM provides a ground path. Run a test lamp between to coil and pcm ground. Each coil will have a different color wire for this. If there is no ground signal. I suspect the PCM may be the issue.

Take care. If you have a chance, let me know what you find or if you have other questions.

Joe

Hi,

You will need to back probe both connectors using a test light. If there is a path to ground, the light should flash. Very carefully, take something small like a paper clip, locate the wire at the PCM, and connect the ground side to that connector. On the opposite side, the coil, back probe the signal ground wire. You are basically running power through the test light to ground, so the light should flash while the engine is cranking. If it doesn't light or flash, then I would double-check the chassis ground in the fender to make sure it is good. If it checks good, at that point, I would suspect an issue with the PCM.

I hope that makes sense. If I was there to show you, it would take two minutes, but it's a little more difficult trying to explain this way.

Regardless, let me know if that helps or if you have other questions.

Joe

You are very welcome. I just hope I can help.

Take care,

Joe