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Service bulletins for the 2026 Jeep Grand Cherokee

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

274 on file from NHTSA, as of 2026-10-19.

About P0300 on the 2026 Jeep Grand Cherokee: what the code means, and the bulletins and recalls about the same components.

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By component

By trouble code

Only bulletins with trouble code: P0300 are shown. Show all

Bulletins, newest first
09-013-26 REV. A2026-10-07. Service bulletin. ENGINE. Engine Runs Rough Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. Customers may also comment on the following: ● Engine runs rough. This bulletin involves replacing all four main chamber spark plugs.
09-023-262026-09-30. Service bulletin. ENGINE. Umbrella Valve Seal Missing From Cylinder Head Cover Vehicle may exhibit a MIL-ON. SYMPTOM: Upon inspection the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have set: ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. This bulletin involves inspecting for a missing umbrella valve seal on the underside of the cylinder head cover and, if necessary, replacing the cylinder head cover.
09-020-262026-08-26. Service bulletin. ENGINE. Umbrella Valve Seal Missing From Cylinder Vehicle may exhibit a MIL-ON. SYMPTOM: Upon inspection the technician may find that one or more of the following Diagnostic Trouble Codes (DTCs) have set: ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. This bulletin involves inspecting for a missing umbrella valve seal on the underside of the cylinder head cover and, if necessary, replacing the cylinder head cover.
09-017-26 REV. A2026-08-26. Service bulletin. ENGINE. Umbrella Valve Seal Missing From Cylinder Head Cover Customer may experience a MIL-ON and/or an indication of low engine oil level. SYMPTOM: Upon inspection the technician may find the following: 1. One or more of the following Diagnostic Trouble Codes (DTCs) have set: ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. 2. Engine oil level is low. IMPORTANT! If none of above symptoms are present, this TSB does NOT apply. This bulletin involves inspecting the engine oil level, possibly inspecting for a missing umbrella valve seal on the underside of the cylinder head cover and, if necessary, replacing the cylinder head cover.
09-017-262026-08-13. Service bulletin. ENGINE. Umbrella Valve Seal Missing From Cylinder Head Cover Customer may experience a MIL-ON and/or an indication of low engine oil level. SYMPTOM: Upon inspection the technician may find the following: 1. One or more of the following Diagnostic Trouble Codes (DTCs) have set: ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. 2. Engine oil level is low. IMPORTANT! If none of above symptoms are present, this TSB does NOT apply. This bulletin involves inspecting the engine oil level, possibly inspecting for a missing umbrella valve seal on the underside of the cylinder head cover and, if necessary, replacing the cylinder head cover
09-013-262026-07-18. Service bulletin. ENGINE. Engine Runs Rough Customers may experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle may SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● P0300-00 - Random/Multiple Cylinder Misfire Detected. ● P0301-00 - Cylinder 1 Misfire. ● P0302-00 - Cylinder 2 Misfire. ● P0303-00 - Cylinder 3 Misfire. ● P0304-00 - Cylinder 4 Misfire. Customers may also comment on the following: ● Engine runs rough. This bulletin involves replacing all four main chamber spark plugs.
18-058-262026-06-16. Service bulletin. POWER TRAIN. Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must exhibit/set one of the following Diagnostic Trouble Codes (DTCs): ● P1CEA - Boost Side Evap Purge System Performance. ● P0300-00 - Random/Multiple Cylinder Misfire Detected ● P0301-00 - Cylinder 1 Misfire ● P0302-00 - Cylinder 2 Misfire ● P0303-00 - Cylinder 3 Misfire ● P0304-00 - Cylinder 4 Misfire Customers may also experience one or more of the following: ● Engine RPM fluctuations at low vehicle speeds after extended idling. ● An ignition-off draw or battery drain condition. ● Sluggish engine performance and misfires. ● Engine knocking when the accelerator is pressed hard or quickly This bulletin involves inspecting and possibly reprogramming the PCM and Transmission Control Module (TCM) with the latest available software.
18-044-262026-03-25. Service bulletin. ENGINE. Flash: Powertrain Control Module (PCM) Updates Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs): ● **P0111-00 - Intake Air Temperature Sensor 1 Circuit Range Performance Bank 1. (In Active or Stored status) ● P0071-00 - Ambient Air Temperature Sensor Performance. (In Active or Stored status) ● P0072-00 - Ambient Air Temperature Sensor Circuit "A" Low. (In Active or Stored status) ● P0073-00 - Ambient Air Temperature Sensor Circuit "A" High. (In Active or Stored status) ● P0011-00 - Bank 1 Camshaft 1 Position Timing Over Advanced Or. (In Active or Stored status) ● P25E4-00 - B Camshaft Position - Unable To Achieve Locked Position Bank 1. (In Active or Stored status) ● P05BD-00 - Stop-Start Mode Switch Range/Performance. (In Active or Stored status) ● P0116-00 - Engine Coolant Temperature Sensor 1 Performance. (In Active or Stored status) ● P062B-00 - Internal Control Module Fuel Injector Control Performance. (In Active or Stored status) ● P0604-00 - Internal Control Module Random Access Memory Ram Error. (In Active or Stored status) ● P060C-00 - Internal Control Module Main Processor Performance. (In Active or Stored status)** ● P018B-00 - Fuel Pressure Sensor "B" Circuit Range/performance. **(In Active or Stored status)** ● P1CEA-00 - Boost Side EVAP Purge System Performance. **(In Active or Stored status)** ● P06DD-00 - Engine Oil Pressure Control Circuit Performance/Stuck Off. **(In Active or Stored status)** ● P00C6-00 - Fuel Rail Pressure Too Low - Engine Cranking. **(In Active or Stored status)** ● P0300-00 - Multiple Cylinder Misfire. **(In Active or Stored status)** Customers may also experience one or more of the following: ● **Oil Level High Warning in the Instrument Panel Cluster (IPC).** ● Fully Autonomous Parking Assist (FAPA) is not deactivated when accelerator pedal is pressed. ● Vehicle is not heating up fast enough at freezi

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.