# P0306 on the 2018 Jeep Grand Cherokee

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

## Bulletins for this model year that name P0306

- [11018482](https://open.wenmarpro.com/bulletins/11018482), 2025-05-20: "Misfire Diagnostic Trouble Codes \(DTCs\), Rough Idle, Valvetrain Noise Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle may exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● P0301 \- Cylinder 1 Misfire. ● P0302 \- Cylinder 2 Misfire. ● P0303 \- Cylinder 3 Misfire. ● P0304 \- Cylinder 4 Misfire. ● P0305 \- Cylinder 5 Misfire. ● P0306 \- Cylinder 6 Misfire. Customers may comment on one or more of the following: ● Rough idle. ● Valvetrain noise. "
- [10220091](https://open.wenmarpro.com/bulletins/10220091), 2022-09-15: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following \(DTCs\) have been set:P06EF \- Engine Restart Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification test \(SLVT\) to determine if a leak is present in the system. P0300 \- Multiple Cylinder Misfire. P0301 \- Cylinder 1 Misfire. P0302 \- Cylinder 2 Misfire. P0303 \- Cylinder 3 Misfire. P0304 \- Cylinder 4 Misfire. P0305 \- Cylinder 5 Misfire. P0306 \- Cylinder 6 Misfire. In addition, customers may experience the following condition:Engine will auto stop and will not auto restart or the engine will auto start and this will result in a misfire, requiring customer to shift into park and manually restart vehicle. Other enhancements included in this update:Improvement for Engine Stop/Start \(ESS\) System.
- [10169239](https://open.wenmarpro.com/bulletins/10169239), 2019-12-16: Flash: Powertrain Control Module \(PCM\) Updates This bulletin involves reprogramming the PCM with the latest available software. Customers may experience a Malfunction Indicator Lamp \(MIL\) illumination. Upon further investigation the technician may find one or more of the following \(DTCs\) have been set:P06EF \- Engine Restart Performance. P0456 \- EVAP System Small Leak.If DTC P0456 is present use the wiTECH Small Leak Verification test \(SLVT\) to determine if a leak is present in the system. P0300 \- Multiple Cylinder Misfire. P0301 \- Cylinder 1 Misfire. P0302 \- Cylinder 2 Misfire. P0303 \- Cylinder 3 Misfire. P0304 \- Cylinder 4 Misfire. P0305 \- Cylinder 5 Misfire. P0306 \- Cylinder 6 Misfire. In addition, customers may experience the following condition:Engine will auto stop and will not auto restart or the engine will auto start and this will result in a misfire, requiring customer to shift into park and manually restart vehicle. Other enhancements included in this update:Improvement for Engine Stop/Start \(ESS\) System.