I have a 2006 TL with 165000 miles. I owned it 5 years trouble free. I recently drove it on a 5 hour trip. 2 hours into my trip
I noticed that the AC blower was blowing but air volume out the vents had decreased. I turned off the compressor for a few minutes and it began blowing hard again...so the rest of the trip I repeated this. Then on my way home the car started to misfire. I made it to a garage..they diagnosed a melted coil pack...not sure which cylinder. It took them 7 or 8 hours to get the fused coil pack out
Then they replaced all coil packs and plugs and a plugged exhaust catalytic converter..one hour after I left the garage the exact same thing started happening... misfiring badly...I barely got it home...now it won't crank at all....can anyone identify the underlying problem causing this...also the engine light as well as the traction control were illuminated....also why did all these problems happen at the same time? AC problem ...melted coil? Any response would be most appreciated...sorry for the long post.

 

Initial guess is the ECU got wet. Search the forums for wet ECU and you will probably find similar stories.

 

I second a wet ecu... Was it raining?

 

No rain at sunny Florida the whole trip...any ideas about why the AC problem and then the misfiring ..or could that be a coincidence..Ive I had zero problems for 5 years.

 

Can be related indeed


Read here: https://www.google.com/search?rlz=1C...60.leQF7Yzyjeo

https://acurazine.com/forums/3g-tl-p...happen-792516/
https://acurazine.com/forums/3g-tl-p...e-help-959995/


Clogged A/C line causes water back up to leak onto the ECU frying it.

 

I've heard that ECU can get wet either way from clogged sunroof drain hoses and also ac evaporator drain hose plugged and leaking onto the ECU. I'd say your ECU is more than likely fried considering you were running the AC when everything went south. That would explain a melted coil pack too. Wet ecu+more resistance=overheated coils.

 

Ding, ding, ding!!

Reduced A/C flow (evaporator froze over) plus melted coil pack = blocked A/C drain tube which caused water to drip down onto the ECU.

ECU is f'd. And you probably fried one or more of the new coil packs. It should be fine once you replace the ECU and clear the drain tube and replace the pack/s. You're looking at $1K+. Good luck!!

 

The ecu supplies the ground signals to the coil packs and tells them when to fire. It only supplies ground to complete the circuit for a fraction of a second. When water shorts the ECU, the coil(s) will get a longer or even indefinite ground signal, keeping them juiced until they get so hot that they melt. I wouldn't say all of your coils are "ruined", but some of them certainly had their lifespan considerably shortened.