Dirty Coils on Jeep Vehicles?
This bulletin applies to the 2015-2018 Jeep Renegade, the 2015-2019 Cherokee and the 2017-2018 Compass. The MIL may be on and the following DTCs may be set: P0300, P0301, P0302, P0303 and P0304.
The problem may be poor connections at the ignition coils. Clean the areas around all coils. Remove the coils. Remove the boot from each coil. The boot seat on the coil bottom flange should be free of debris. If not, clean with a clean rag. Use parts cleaner MOPAR 04318040AC to prepare the coil surface. Use at air temperature and allow to air dry. Make sure the spring is inside each new boot. Assemble the boots onto the coils, pushing and turning until fully seated. Place a small, 360-degree bead of MOPAR Molykote G-5008 lube along the inside opening of the coil boots, about 1-2 mm from the chamfered edge but not on the chamfered surface. Use only the MOPAR grease, as other grease may cause damage to the boots.
Reinstall the coils, clear DTCs and start the engine. Let run for at least one minute. If still running rough, continue with normal diagnostics.