For the last week I have had a slightly rough idle, not as bad as I've experienced in other vehicles but in my Patriot, which I have owned for about 6 months, it caused the ESP light and ETC light to come on. This prevented me from going over 40mph and the lights went off after I turned the vehicle off and turned it back on again. This has happened twice. The first time the check engine light went off before I could get to Autozone to find out what code it was throwing. This time happened on my way to work. I'm just trying to get a feel for what may be causing it. The first time it was idling rough but down when I started the car. This second time it was revving up to about 3k rpms when I started the car. Both times the lights came on after I was already driving it and the idle seemed fine. The car is due for an oil change but I didn't think this had anything to do with my idle. I live paycheck to paycheck and I'm trying to have an idea of what kind of repair I'm looking at.
My car has 54100 miles.
My car has an automatic transmission.
Hi there. I wouldn’t get too worried. It is normal for the ESP and ETC lights to come on when the Check Engine Light (CEL) does. They are Electronic Stability Program and Electronic Traction Control. Both are tied into the ABS system.
If the engine or transmission is not working properly, these systems will be disabled. The lights come on to inform you of this. If the engine is rough at idle, it is misfiring. The engine computer can detect even the slightest misfire. When it does it will set a code and turn on the CEL. The code will remain stored even if the light goes out.
Misfires can damage the catalytic converter. This is why the computer will only allow you to go 40mph. It reduces the power output of the engine to prevent more damage. Have the codes read out for you if you wish. Misfire codes are P0300-P0304.
For the rough idle, you will still need someone to diagnose why it is misfiring. If I were to guess, I would think you have a bad ignition coil. There is one for each cylinder. If you would like to have all of this checked, a certified technician from YourMechanic can come to your car’s location to diagnose the rough idle (as well as any other problems) and can advise you on any suggested or urgent repairs.
Have a car question? Get free advice from our top-rated mechanics.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing