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Manufacturer communication · Service bulletin

Jeep bulletin 18-050-26

What it saysFlash: 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… NHTSA’s full summary ↓

Jeep filed this with NHTSA as a service bulletin dated Apr 18, 2026, received Apr 22, 2026, about the engine. It names 1 model year (2021). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.

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What the bulletin says

Source: NHTSA's summary of the manufacturer's communication

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. 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.

Trouble codes it names: P0300 P0301 P0302 P0303 P0304 P0305 P0306

Kind Service bulletin Manufacturer date Apr 18, 2026 Received by NHTSA Apr 22, 2026 Components Engine, Power Train

Document filed under this number

DocumentKindDatedNHTSA idAt NHTSA
18-050-26Service bulletinApr 18, 202611031455not found

The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.

Model years it names

Source: as the manufacturer filed them

A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.

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What owners reported

Source: NHTSA complaint database

Owners of the 1 model year this bulletin names have filed 487 complaints with NHTSA since 2015. 132 of them name Power Train, Engine — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.

On the 2021 Jeep Grand Cherokee, the 15 owners who gave an odometer reading for Power Train reported it at a median of 34,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.

2021 Jeep Grand Cherokee L. I was idling at a light, which means the engine had auto-shut off. The light turned green and I stepped on the accelerator. Car kicked back on like normal and I got back up to speed ~45 mph.

2021 Jeep Grand Cherokee · Engine · filed with NHTSA Jun 23, 2025

A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.

More bulletins about the engine

Source: same model, same component group

86 other manufacturer communications filed against the Jeep Grand Cherokee under the same component group (engine), newest first. The eight newest are listed; the rest are on the Jeep list.

NumberKindDatedNHTSA’s summary
09-023-26Service bulletinSep 25, 2026Umbrella Valve Seal Missing From Cylinder Head Cover Vehicle may exhibit a MIL-ON. SYMPTOM: Upon inspection the technician may find that one…
S2609000011Service bulletinSep 11, 2026MIL-On and/or Engine Oil Leak
9100363 Rev 3Service bulletinAug 26, 2026Turbocharger Kit Please note many parts of the Turbo Assembly can be serviced separately and complete turbo replacement may not be necessary…
ID-26-38 REV.AWarranty extensionAug 25, 2026ID-26-38 Rev. A Dealer Incentive for the Completion of Customer Satisfaction Notification 66D
D-26-18 REV.AWarranty extensionAug 25, 2026D-26-18 Rev. A Dealer Incentive for the Completion of Customer Satisfaction Notification 66D
114238Warranty extensionAug 24, 2026Dealer Incentive for the Completion of Customer Satisfaction Notice (CSN) 66D
114236Warranty extensionAug 24, 2026Dealer Incentive for the Completion of Customer Satisfaction Notice (CSN) 66D
S2618000003Service bulletinAug 21, 2026MIL-On, Engine Runs Rough

Quote the number at the service desk. It is what the dealer’s system is keyed on.

Every manufacturer communication NHTSA holds for Jeep, by the number printed on the letter.

Photo: Christian Buehner / Unsplash

Common questions

Source: NHTSA, 49 CFR 579.5

Is Jeep 18-050-26 a recall?

No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.

Is the 18-050-26 repair free?

Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way.

Which vehicles does 18-050-26 cover?

The manufacturer filed it against 1 model year: 2021 Jeep Grand Cherokee. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.