I replaced the spark plugs at 59.7K miles. I didn't replace the ignition coils. The CX-5 has had slower starts and degraded performance recently. Spark plugs were due, but no other problems and she has cranked reliably since day one.

As I said, replaced the spark plugs, but not the ignition coils and the car cranked just after completion. Left it for a couple of hours, now it won't cranked. Went back at removed each plug one-by-one, reset the ignition coil and tried to crank the engine after each one. Same problem. The "ignition" comes one, you can hear the electrical system "click" on, but the engine does not turn over. No typical clicking sounds from a dead battery. No warning lights. Push to start and the gauges peg and the dash returns to the Depress the Brake and Push Start message. No oscilloscope test on the ignition system.

Could this be as simple as ignition coils?
Or am I missing something?

 

Welcome to the forum

 

You either damaged something during the spark plug change or IDK….but it’s not the coils.

Do you or did you scan the ECU just curious what DTCs are coming up.

 

Thanks for the welcome and the notes. My initial thought was it was not the ignition coils. Haven't run a scan as of yet. Just tried putting the old plugs back in, just for fun and giggles, same issue.

 

remove a coil , look into the boot and make sure the spring is still there and very visible

 

If it only clicks when you now try to start test your battery. If the coils were fine before there still fine.

 

As Charlescrown replied to your issue (hard starting not plugs) could simply be because of a bad battery.
Get your battery load tested to see if it is any good, before doing anything else.

 

Sorry I fixated on the coil removal and not reading your full response. Often times without knowing when changing what is a simple job when replacing the coils and not using any dielectric grease the boot will go on but the spring contact gets miss aligned and you will get a engine start but a miss-fire cylinder code.
So now reading your response and the other 2 members I am also in agreement that it was simply coincidence that during your service your battery choose to fail. Based on exactly what you said I am confident that when you change your battery to 12.50 min volts and have it load tested you will be getting a new battery.