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Service bulletin 18-051-26

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11031456
Published by NHTSA2026-04-22
Manufacturer's number18-051-26
Manufacturer's date2026-04-18
NHTSA componentENGINE; POWER TRAIN

NHTSA's 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.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Transmission and driveline

Trouble codes named

C053D, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P152F, P2066

Vehicles listed
JEEP GRAND CHEROKEE2023
JEEP GRAND CHEROKEE L2023

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
26V4130002026-06-30. POWER TRAIN:AUTOMATIC TRANSMISSION:GEAR POSITION INDICATION (PRNDL)
20256172025-11-06. Engine
25V7660002025-11-06. ENGINE

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
S26210000042026-10-07. Service bulletin. The Customer May Complain About a Popping Noise, Grinding Noise, or an Intermittent No Reverse or Forward Transmission Engagement. The Tech May Find Damaged and/or Worn Transmission Output Shaft Splines (850RE Transmission Only)
S26090000112026-09-17. Service bulletin. MIL-On and/or Engine Oil Leak
9100363 Rev 32026-09-03. Service bulletin. Turbocharger Kit Please note that many turbo components are serviceable separately and full turbo replacement may not be required. If the turbo is being inspected for: Noise/Rattle: Inspect heat shield fasteners for looseness and check the wastegate actuator/linkage for binding. The actuator kit is serviced separately. Oil Leak: Inspect the turbo oil feed O-ring area for leaks. O-ring is serviced separately.
1135282026-07-23. Service bulletin. SHAFT - AXLE HALF
1135292026-07-23. Service bulletin. SHAFT - AXLE HALF
1126392026-07-08. Service bulletin. THROTTLE BODY – NONE
1126402026-07-08. Service bulletin. THROTTLE BODY – NONE
1128422026-07-02. Service bulletin. BOLT - HEX FLANGE HEAD
21-041-26 REV. A2026-07-02. Service bulletin. Transmission Auxiliary Oil Pump Failure Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must SYMPTOM: exhibit/set **one or more the following Diagnostic Troubles Code (DTCs): ● U0287-00 - Lost Communication With Transmission Fluid Pump Module 1.** ● P0B0D-00 - Electric/Auxiliary Transmission Fluid Pump Motor Control Module. Customers may also comment on the following: ● Vehicle is in limp mode. This bulletin involves replacing the transmission oil pump.
1123412026-06-03. Warranty extension. ID-26-04 Rev. A Addition of 2.0L T4 Long Block or Complete Engine to the Powertrain Service Center (PTSC) Pre-Approval Program To clarify when an OEM part and the Recall Campaign part should be used. The original bulletin announced the addition of the 2.0L T4 Long Block or Complete Engine (Sales Codes EC1, EC2, and ECX) to the Powertrain Pre-Approval process.