{"nhtsa_id":11031456,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-04-22","date":"2026-04-18","document_id":"18-051-26","mfr_campaign":null,"replaces":null,"component":"ENGINE; POWER TRAIN","mfr_system":null,"summary":"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):** ● **P0300 - Multiple Cylinder Misfire - In Active or Stored status set during cold start catalyst heating. ● P0301 - Cylinder 1 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0302 - Cylinder 2 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0303 - Cylinder 3 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0304 - Cylinder 4 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0305 - Cylinder 5 Misfire - In Active or Stored status set during cold start catalyst heating. ● P0306 - Cylinder 6 Misfire - In Active or Stored status set during cold start catalyst heating. ● P2066 - Fuel Level Sensor 2 Performance. ● P152F - Engine Hood Switch 2 / Engine Hood Switch 1 Correlation.** ● C053D - Brake Pressure Sensor 1 Performance. **Customers may also comment on one or more of the following: ● Check engine illuminates when fueling the vehicle while the engine is running. ● Vehicle has a noticeable misfire. ● Vehicle idles rough. ● Engine noise. NOTE: Noise is heard coming from the valvetrain.** **In addition, the following software enhancement is available: ● Update to prevent customers from driving their vehicles while the Electric Park Brake (EPB) is engaged. Engine torque will be limited to prevent the Rear Drive Unit from being damaged. NOTE: Previously, the EPB would remain engaged without any torque limit which could lead to the Rear Drive Unit being damaged/broken.** This bulletin involves reprogramming the PCM with the latest available software.","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031456-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031456-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11031456","components":[{"id":"engine","name":"Engine","parent":null},{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":["C053D","P0300","P0301","P0302","P0303","P0304","P0305","P0306","P152F","P2066"],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":2023,"year_to":2023,"match":"exact","vehicle_ids":["2023_jeep_grand-cherokee"]},{"make":"JEEP","model":"GRAND CHEROKEE L","year_from":2023,"year_to":2023,"match":"exact","vehicle_ids":["2023_jeep_grand-cherokee-l"]}],"as_of":"2026-10-19","note":"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.","attribution":[]}