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 st
full bulletin at NHTSA ↗2021 Jeep Grand Cherokee L powertrain problems
moderate 11 complaints filed with NHTSA · avg repair $2,500 · see powertrain across all vehicles →
Complaints
11
Recalls
0
Avg fix
$2,500
When does it fail?
Of the 11 powertrain complaints filed for the 2021 Jeep Grand Cherokee L, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Of the 4 model years of Jeep Grand Cherokee L we track for powertrain problems, this one carries the most owner complaints on file — 11.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
The vehicle will exhibit a service transmission/check engine warning indicator for the following transmission models: 845RE, 8HP45, 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV, 8HP75-LCV, 8HP90, 8HP95. Transmissions may exhibit the following diagnostic codes: P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
full bulletin at NHTSA ↗Service transmission/check engine warning indicator for the 850RE, 8HP50, 8HP70, 8HP75, 8HP75-PHEV transmissions that have fault codes P07E4, P1DB2, P0716, P1B14, P0733, P1D90, P1DB7, P1B13.
full bulletin at NHTSA ↗The customer is experiencing a clicking or pop noise from the steering knuckle and bearing area during turns while driving.
full bulletin at NHTSA ↗SWITCH - TRANSFER CASE, RIDE HEIGHT, TERRAIN SELECT
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 3 most recent
Jeep grand Cherokee L, the 3.7L V6 engine in the Jeep has experienced camshaft and valvetrain issues, often related to wear and lubrication problems. Sides a ticking and rough running/banging engine. Caused by faulty camshafts. The company knows the cam shafts are faulty, in Michigan the part is on back order by over 10,000 parts. The company is no longer creating the camshaft because of its…
The contact owns a 2021 Jeep Grand Cherokee L. The contact stated while driving 70 MPH on an interstate and depressing the brake pedal to avoid a crash, the automatic emergency braking system suddenly engaged, and the vehicle experienced a drivetrain failure. The contact was able to pull over to the side of the road. There was no warning light illuminated. The vehicle was towed to the local…
The vehicle has twice gotten stuck in third gear. While driving, as it's shifting from third to fourth, will get stuck in third and clunk, and then rev. The engine light will come on, and it forces you to pull over. The manual shifters do not work either. You have to pull over, shut the car down, and restart. The engine light comes on but no errors are logged, and the engine light clears itself a…
Had powertrain trouble with your 2021 Jeep Grand Cherokee L?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2021 Jeep Grand Cherokee L?
It's a documented issue but not catastrophic. 11 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Based on the 11 complaints filed, powertrain issues most often appear around 84,350 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Jeep/Grand Cherokee L.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.